function ValidateEmail() {
	var emailID=document.contactform.email
	
	if ((emailID.value==null)||(emailID.value=="")){
		alert("Email address is mandatory!")
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	if (echeck(emailID.value)==false){
		emailID.value=""
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	//document.contactform.submitbut.disabled = false;
	return true;
}


function checkform() {

	var firstname=document.contactform.firstname;
	var lastname=document.contactform.lastname;
	var message=document.contactform.message;
	var subject=document.contactform.subject;
	
	if ((firstname.value==null)||(firstname.value=="")){
		alert("First Name is mandatory!")
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	if ((lastname.value==null)||(lastname.value=="")){
		alert("Last Name is mandatory!")
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	if (ValidateEmail()==false){
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	if ((subject.value==null)||(subject.value=="")){
		alert("Subject is mandatory!")
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	if ((message.value==null)||(message.value=="")){
		alert("Message field should not be empty!")
		//document.contactform.submitbut.disabled = true;
		return false;
	}
	//document.contactform.submitbut.disabled = false;
	return true;
}

function echeck(str) {

		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if (str.indexOf(at)==-1){
		   alert("Invalid Email address!")
		   return false
		}
		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Invalid email address!")
		   return false
		}
		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Invalid email address!")
		    return false
		}
		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Invalid email address!")
		    return false
		 }
		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Invalid email address!")
		    return false
		 }
		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Invalid email address!")
		    return false
		 }
		 if (str.indexOf(" ")!=-1){
		    alert("Invalid email address!")
		    return false
		 }
 		 return true					
	}