String.prototype.trim = function() {
	return this.replace(/^\s+|\s+$/g,"");
}
String.prototype.ltrim = function() {
	return this.replace(/^\s+/,"");
}
String.prototype.rtrim = function() {
	return this.replace(/\s+$/,"");
}
String.prototype.isNumeric = function() {
	if (this == ""){ return false; } for(var i=0;i<this.length;i++){ if(!isDigit(this.charAt(i))){ return false; }} return true;
}