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+$/,"");
}

function checkEmail(email, msg) {
	email.value=email.value.trim();
	if(email.value=="") {
		email.value = msg;
		return false;
	}
	var filter = /^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email.value)) {
		alert('Please provide a valid email address');
		this.focus();
		return false;
	}
}

function clearEmail(email, msg) {
	if(email.value == msg) {
		email.value=""
	}
}