function validateForm(){
	var errorMessage = "";
	errorMessage += checkMandatoryField(document.forms[0].name, "name");
	//errorMessage += checkMandatoryField(document.forms[0].email, "email");
	errorMessage += echeck(document.forms[0].email.value);
	errorMessage += checkMandatoryField(document.forms[0].subject, "subject");
	errorMessage += checkMandatoryField(document.forms[0].message, "message");
	
	if(errorMessage.length > 0){
		alert(errorMessage);
		return false;
	}else{
		return true;
	}
}


function checkMandatoryField(formField, fieldName){
	var error = "";
	if((formField.value.length==0) || formField.value==null){
		if(fieldName == "name"){
			error = "* Please enter your name\n";
		}else if(fieldName == "email"){
			error = "* Please enter your email address\n";
		}else if(fieldName == "subject"){
			error = "* Please enter a subject\n";
		}else if(fieldName == "message"){
			error = "* Please enter your message\n";
		}
	}
	
	return error;
}

function echeck(str) {
		var error = "";
		var at="@";
		var dot=".";
		var lat=str.indexOf(at);
		var lstr=str.length;
		var ldot=str.indexOf(dot);
		if (str.indexOf(at)==-1){
		   error = "* Invalid e-mai address \n";
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   error = "* Invalid e-mai address \n";;
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    error = "* Invalid e-mai address \n";
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    error = "* Invalid e-mai address \n";
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    error = "* Invalid e-mai address \n";
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    error = "* Invalid e-mai address \n";
		 }
		
		 if (str.indexOf(" ")!=-1){
		    error = "* Invalid e-mai address \n";
		 }

 		 return error;					
	}