<script language="javascript">
<!--
var string1 = "These quotes \"are\" valid!";
var string2 = 'Isn\'t JavaScript great?';
var string3 = "These quotes 'are' valid!";
var string4 = 'These quotes "are" valid!';
document.write("This is string1:"+string1+"<br>");
document.write("This is string2:"+string2+"<br>");
document.write("This is string3:"+string3+"<br>");
document.write("This is string4:"+string4);
//-->
</script>