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 validate_email(){
	
	var email=document.getElementById("email");
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(email.value.trim())) {
		return true;
	} else {
		alert("please enter a valid email address");
		document.getElementById("email").focus();
		return false;
	}
}

function valid_email_address(emailFieldId){
	
	var email=document.getElementById(emailFieldId);
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(email.value.trim())) {
		return true;
	} else {
		return false;
	}
}
function validate_name(){
	if (document.getElementById("name").value.trim().length>0){
		return true;
	} else {
		alert("please enter your name");
		document.getElementById("name").focus();
		return false;
	}		
}

function validate_content(){
	if (document.getElementById("message").value.trim().length>0){
		return true;
	} else {
		alert("please enter your message");
		document.getElementById("message").focus();
		return false;
	}		
}
function validate(){
	if (validate_email() && validate_name() && validate_content() ){
		return true;
	}
	else {
		return false;
	}
}
function submitform(){
	if (validate()) {
		document.form1.submit();
	};
};
function clearform() {

	document.form1.message.value="";
	document.form1.name.value="";
	document.form1.email.value="";
}