function changepic()
{
   document.images.faceimg.src="images/face/"+document.messageform.face.options[document.messageform.face.selectedIndex].value;
}
function changebrow()
{
   document.images.browimg.src="images/brow/"+document.messageform.brow.options[document.messageform.brow.selectedIndex].value;
}
function checklogin()
{
	if (document.messageform.username.value == '')
	{       
		alert("请输入姓名！");
		document.messageform.username.focus();
		return false;
	}
	if (document.messageform.subject.value == '')
	{
		alert("请输入主题！");
		document.messageform.subject.focus();
		return false
	}
	if (document.messageform.tel.value == '')
	{
		alert("请输入电话！");
		document.messageform.tel.focus();
		return false;
	}
	if (document.messageform.address.value == '')
	{
		alert("地址不能为空！");
		document.messageform.address.focus();
		return false;
	}
	if (document.messageform.zipcode.value == '')
	{
		alert("邮编不能为空！");
		document.messageform.zipcode.focus();
		return false;
	}
	if (document.messageform.content.value == '')
	{
		alert("请输入内容！");
		document.messageform.content.focus();
		return false;
	}
	return true;
}