function isNum(str)
  {
    for(i=0;i<str.length;i++)
    {
     if(str.charAt(i)>="0" && str.charAt(i)<="9")
     {
     }
     else
     {
	return 0;
     }
    }
     return 1;
  }
function checkGbookForm()
 {
	if (document.form1.name.value=="")
	{
	  alert("Please input your name.");
	  document.form1.name.focus();
	  return false;
	}
	if (document.form1.name.value.length>20)
	{
		alert("Long name,At present, in terms of:"+document.form1.content.value.length)
		document.form1.name.focus();
		return false;
	}
	if (document.form1.qq.value!="" && !(isNum(document.form1.qq.value)))
	{
		alert("QQ must be a figure.");
		document.form1.qq.focus();
                document.form1.qq.select();
		return false;
	}
	if (document.form1.qq.value.length>10)
	{
		alert("The QQ word number is very long.")
		document.form1.qq.focus();
		return false;
	}
	if (document.form1.mail.value.length>30)
	{
		alert("Long-mail addresses.")
		document.form1.mail.focus();
		return false;
	}
	if (document.form1.home.value.length>200)
	{
		alert("Home page address is too long.")
		document.form1.home.focus();
		return false;
	}
	if (document.form1.content.value=="")
	{
		alert("Please input content.")
		document.form1.content.focus();
		return false;
	}
	if (document.form1.content.value.length>1000)
	{
		alert("Content is very long,At present, in terms of:"+document.form1.content.value.length)
		document.form1.content.focus();
		return false;
	}
		if (document.form1.rndNum.value=="")
	{
		alert("Please import authentication code");
		document.form1.rndNum.focus();
		return false;
	}
	return true;
	 
 }