var bIsCatchTitleBar = false;
var offsetX = 0;
var offsetY = 0;
var nowX = 0;
var nowY = 0;

function catchTitleBar(e){
bIsCatchTitleBar = true;
offsetx=event.clientX;
offsety=event.clientY;
nowX=parseInt(popupContainer.style.left);
nowY=parseInt(popupContainer.style.top);
popupContainer.setCapture();
document.onmousemove = moveTitleBar;
}
function releaseTitleBar(e){
bIsCatchTitleBar = false;
popupContainer.releaseCapture();
document.onmousemove = null;
}
function moveTitleBar(e){
if(bIsCatchTitleBar){
popupContainer.style.left=nowX+event.clientX-offsetx; 
popupContainer.style.top=nowY+event.clientY-offsety;
}
}

document.onmouseup = releaseTitleBar;