function $(obj) {
	return document.getElementById(obj);
}

String.prototype.startsWith = function(str) {
	return ( this.match("^"+ str) == str );
}

String.prototype.endsWith = function(str) {
	return ( this.match(str +"$") == str );
}

String.prototype.strip = function() {
	return this.replace(/^\s+/, '').replace(/\s+$/, '');
}

Object.prototype.isString = function(val) {
	return typeof val == "string";
}