Javascript trim with Regular Expressions

gistfile1.js

<script type="text/javascript">
//Javascript trim() example
String.prototype.trim = function() { return this.replace(/^\s+|\s+$/g, ""); };

//Usage:
var str = " foo bar ";
alert("Original string: '" + str + "'");
str = str.trim();
alert("Trimmed string: '" + str + "'");
</script>