return left + spaces + right;
	}

	// This function process one line for 'smart tabs'
	function ProcessLine(line, tabSize)
	{
		if(line.indexOf(tab) == -1)
			return line;

		var pos = 0;

		while((pos = line.indexOf(tab)) != -1)
		{
			// This is pretty much all there is to the 'smart tabs' logic.
			// Based on the position within the line and size of a tab, 
			// calculate the amount of spaces we need to insert.
			var spaces = tabSize - pos % tabSize;
			
			line = InsertSpaces(line, pos, spaces);
		}
		
		return line;
	}

	// Go through all the lines and do the 'smart tabs' magic.
	for(var i = 0; i < lines.length; i++)
		result += ProcessLine(lines[i], tabSize) + '\n';
	
	return result;
}

dp.sh.Highlighter.prototype.SwitchToList = function()
{
	// thanks to Lachlan Donald from SitePoint.com for this <br/> tag fix.
	var html = this.div.innerHTML.replace(/<(br)\/?>/gi, '\n');
	var lines = html.split('\n');
	
	if(this.addControls == true)
		this.bar.appendChild(dp.sh.Toolbar.Create(this));

	// add columns ruler
	if(this.showColumns)
	{
		var div = this.CreateElement('div');
		var columns = this.CreateElement('div');
		var showEvery = 10;
		var i = 1;
		
		while(i <= 150)
		{
			if(i % showEvery == 0)
			{
				div.innerHTML += i;
				i += (i + '').length;
			}
			else
			{
				div.innerHTML += '&middot;';
				i++;
			}
		}
		
		columns.className = 'columns';
		columns.appendChild(div);
		this.bar.appendChild(columns);
	}

	for(var i = 0, lineIndex = this.firstLine; i < lines.length - 1; i++, lineIndex++)
	{
		var li = this.CreateElement('LI');
		var span = this.CreateElement('SPAN');
		
		// uses .line1 and .line2 css styles for alternating lines
		li.className = (i % 2 == 0) ? 'alt' : '';
		span.innerHTML = lines[i] + '&nbsp;';

		li.appendChild(span);
		this.ol.appendChild(li);
	}
	
	this.div.innerHTML	= '';
}

dp.sh.Highlighter.prototype.Highlight = function(code)
{
	function Trim(str)
	{
		return str.replace(/^\s*(.*?)[\s\n]*$/g, '$1');
	}
	
	function Chop(str)
	{
		return str.replace(/\n*$/, '').replace(/^\n*/, '');
	}

	function Unindent(str)
	{
		var lines = dp.sh.Utils.FixForBlogger(str).split('\n');
		var indents = new Array();
		var regex = new RegExp('^\\s*', 'g');
		var min = 1000;

		// go through every line and check for common number of indents
		for(var i = 0; i < lines.length && min > 0; i++)
		{
			if(Trim(lines[i]).length == 0)
				continue;
				
			var matches = regex.exec(lines[i]);

			if(matches != null && matches.length > 0)
				min = Math.min(matches[0].length, min);
		}

		// trim minimum common number of white space from the begining of every line
		if(min > 0)
			for(var i = 0; i < lines.length; i++)
				lines[i] = lines[i].substr(min);

		return lines.join('\n');
	}
	
	// This function returns a portions of the string from pos1 to pos2 inclusive
	function Copy(string, pos1, pos2)
	{
		return string.substr(pos1, pos2 - pos1);
	}

	var pos	= 0;
	
	if(code == null)
		code = '';
	
	this.originalCode = code;
	this.code = Chop(Unindent(code));
	this.div = this.CreateElement('DIV');
	this.bar = this.CreateElement('DIV');
	this.ol = this.CreateElement('OL');
	this.matches = new Array();

	this.div.className = 'dp-highlighter';
	this.div.highlighter = this;
	
	this.bar.className = 'bar';
	
	// set the first line
	this.ol.start = this.firstLine;

	if(this.CssClass != null)
		this.ol.className = this.CssClass;

	if(this.collapse)
		this.div.className += ' collapsed';
	
	if(this.noGutter)
		this.div.className += ' nogutter';

	// replace tabs with spaces
	if(this.tabsToSpaces == true)
		this.code = this.ProcessSmartTabs(this.code);

	this.ProcessRegexList();	

	// if no matches found, add entire code as plain text
	if(this.matches.length == 0)
	{
		this.AddBit(this.code, null);
		this.SwitchToList();
		this.div.appendChild(this.bar);
		this.div.appendChild(this.ol);
		return;
	}

	// sort the matches
	this.matches = this.matches.sort(dp.sh.Highlighter.SortCallback);

	// The following loop checks to see if any of the matches are inside
	// of other matches. This process would get rid of highligted strings
	// inside comments, keywords inside strings and so on.
	for(var i = 0; i < this.matches.length; i++)
		if(this.IsInside(this.matches[i]))
			this.matches[i] = null;

	// Finally, go through the final list of matches and pull the all
	// together adding everything in between that isn't a match.
	for(var i = 0; i < this.matches.length; i++)
	{
		var match = this.matches[i];

		if(match == null || match.length == 0)
			continue;

		this.AddBit(Copy(this.code, pos, match.index), null);
		this.AddBit(match.value, match.css);

		pos = match.index + match.length;
	}
	
	this.AddBit(this.code.substr(pos), null);

	this.SwitchToList();
	this.div.appendChild(this.bar);
	this.div.appendChild(this.ol);
}

dp.sh.Highlighter.prototype.GetKeywords = function(str) 
{
	return '\\b' + str.replace(/ /g, '\\b|\\b') + '\\b';
}

dp.sh.BloggerMode = function()
{
	dp.sh.isBloggerMode = true;
}

// highlightes all elements identified by name and gets source code from specified property
dp.sh.HighlightAll = function(name, showGutter /* optional */, showControls /* optional */, collapseAll /* optional */, firstLine /* optional */, showColumns /* optional */)
{
	function FindValue()
	{
		var a = arguments;
		
		for(var i = 0; i < a.length; i++)
		{
			if(a[i] == null)
				continue;
				
			if(typeof(a[i]) == 'string' && a[i] != '')
				return a[i] + '';
		
			if(typeof(a[i]) == 'object' && a[i].value != '')
				return a[i].value + '';
		}
		
		return null;
	}
	
	function IsOptionSet(value, list)
	{
		for(var i = 0; i < list.length; i++)
			if(list[i] == value)
				return true;
		
		return false;
	}
	
	function GetOptionValue(name, list, defaultValue)
	{
		var regex = new RegExp('^' + name + '\\[(\\w+)\\]$', 'gi');
		var matches = null;

		for(var i = 0; i < list.length; i++)
			if((matches = regex.exec(list[i])) != null)
				return matches[1];
		
		return defaultValue;
	}
	
	function FindTagsByName(list, name, tagName)
	{
		var tags = document.getElementsByTagName(tagName);

		for(var i = 0; i < tags.length; i++)
			if(tags[i].getAttribute('name') == name)
				list.push(tags[i]);
	}

	var elements = [];
	var highlighter = null;
	var registered = {};
	var propertyName = 'innerHTML';

	// for some reason IE doesn't find <pre/> by name, however it does see them just fine by tag name... 
	FindTagsByName(elements, name, 'pre');
	FindTagsByName(elements, name, 'textarea');

	if(elements.length == 0)
		return;

	// register all brushes
	for(var brush in dp.sh.Brushes)
	{
		var aliases = dp.sh.Brushes[brush].Aliases;

		if(aliases == null)
			continue;
		
		for(var i = 0; i < aliases.length; i++)
			registered[aliases[i]] = brush;
	}

	for(var i = 0; i < elements.length; i++)
	{
		var element = elements[i];
		var options = FindValue(
				element.attributes['class'], element.className, 
				element.attributes['language'], element.language
				);
		var language = '';
		
		if(options == null)
			continue;
		
		options = options.split(':');
		
		language = options[0].toLowerCase();

		if(registered[language] == null)
			continue;
		
		// instantiate a brush
		highlighter = new dp.sh.Brushes[registered[language]]();
		
		// hide the original element
		element.style.display = 'none';

		highlighter.noGutter = (showGutter == null) ? IsOptionSet('nogutter', options) : !showGutter;
		highlighter.addControls = (showControls == null) ? !IsOptionSet('nocontrols', options) : showControls;
		highlighter.collapse = (collapseAll == null) ? IsOptionSet('collapse', options) : collapseAll;
		highlighter.showColumns = (showColumns == null) ? IsOptionSet('showcolumns', options) : showColumns;

		// write out custom brush style
		var headNode = document.getElementsByTagName('head')[0];
		if(highlighter.Style && headNode)
		{
			var styleNode = document.createElement('style');
			styleNode.setAttribute('type', 'text/css');

			if(styleNode.styleSheet) // for IE
			{
				styleNode.styleSheet.cssText = highlighter.Style;
			}
			else // for everyone else
			{
				var textNode = document.createTextNode(highlighter.Style);
				styleNode.appendChild(textNode);
			}

			headNode.appendChild(styleNode);
		}
		
		// first line idea comes from Andrew Collington, thanks!
		highlighter.firstLine = (firstLine == null) ? parseInt(GetOptionValue('firstline', options, 1)) : firstLine;

		highlighter.Highlight(element[propertyName]);
		
		highlighter.source = element;

		element.parentNode.insertBefore(highlighter.div, element);
	}	
}