function checkmessage()
{
	var obj=document.messagefrom;
	if(obj.username.value=="")
	{
		alert("Please enter your name!");
		obj.username.focus();
		return false;
	}
	if(obj.email.value=="")
	{
		alert("Please enter the email!");
		obj.email.focus();
		return false;
	}
	var filter2=/^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/;
	if (!filter2.test(obj.email.value))
	{ 
		alert("E-mail address is incorrect, please re-fill!"); 
		obj.email.focus();
		obj.email.select();
		return false; 
	}
	if(obj.content.value=="")
	{
		alert("Please enter the content of messages!");
		obj.content.focus();
		return false;
	}
}