function check(){
		var form=document.contact_us;
		var first_name=form.first_name.value;
		var last_name=form.last_name.value;
		var email_addr=form.email_addr.value;
		var confirm_email=form.confirm_email.value;
		var system=form.system.value;
		var product=form.product.value;
		var Version=form.Version.value;
		var content=form.content.value;
		if(first_name == ""){
			alert("Please enter your first name!");
			return false;
		}
		if(last_name == ""){
			alert("Please enter your last name!");
			return false;
		}
		if(email_addr == ""){
			alert("Please provide your email address to receive our response!");
			return false;
		}
		if(email_addr != confirm_email){
			alert("Please confirm your email address!");
			return false;
		}
		if(system == ""){
			alert("Please select your operating system!");
			return false;
		}
		if(product == ""){
			alert("Please select a product!");
			return false;
		}
		if(content == ""){
			alert("Please tell us what can we help you!");
			return false;
		}
		return true;
		
	}