function validate() 
{
	if (document.getElementById('name').value == ""){ 
	 	alert ("Please Enter Your Name." )
        document.getElementById('name').focus()        
		 return;}
	else if (document.getElementById('email').value == ""){ 
	 	alert ("Please Enter Your Email." )
        document.getElementById('email').focus()        
		 return;}
	else if(!((document.getElementById('email').value.indexOf(".") > 2) && (document.getElementById('email').value.indexOf("@") > 0))){
	 	alert ("Invalid Email" )
       document.getElementById('email').focus()        
		 return;}
	else if (document.getElementById('phone').value == ""){ 
	 	alert ("Please Enter Your Phone Number." )
        document.getElementById('phone').focus()        
		 return;}
		 else if (document.getElementById('sujet').value == ""){ 
	 	alert ("Please Enter A Subject." )
        document.getElementById('sujet').focus()        
		 return;}
	else if (document.getElementById('comment').value == ""){ 
	 	alert ("Please type A Message." )
        document.getElementById('comment').focus()        
		 return;}
	else{
        document.getElementById('contactform').submit();}
}

<!--

//Disable right mouse click Script

var message="Sorry, you do not have permission to right click.";

///////////////////////////////////
function clickIE4(){
if (event.button==2){
alert(message);
return false;
}
}

function clickNS4(e){
if (document.layers||document.getElementById&&!document.all){
if (e.which==2||e.which==3){
alert(message);
return false;
}
}
}

if (document.layers){
document.captureEvents(Event.MOUSEDOWN);
document.onmousedown=clickNS4;
}
else if (document.all&&!document.getElementById){
document.onmousedown=clickIE4;
}

document.oncontextmenu=new Function("alert(message);return false")

// -->