function String_rtrim(){//right trim a string
	var sTemp=this;
	if(sTemp.length>0){
		while(sTemp.lastIndexOf(' ')==sTemp.length-1){
			sTemp=sTemp.substring(0, sTemp.length-2);
		};
	};
	return sTemp;
}
String.prototype.rtrim=String_rtrim;

function String_ltrim(){//Left trim a string
	var sTemp=this;
	while(sTemp.indexOf(' ')==0){
		sTemp = sTemp.substring(1);
	};
	return sTemp;
}
String.prototype.ltrim=String_ltrim;

function String_trim() { //trim a string
	var sTemp = this;
	sTemp.ltrim();
	sTemp.rtrim();
	return sTemp;
}
String.prototype.trim=String_trim;