function Check_Form_Validator(theform)

{

if (theform.username.value=="")

{

alert('请输入用户名！');

theform.username.focus();

return false;

}

if (theform.username.value.length < 2)

{

alert('你的用户名请至少输入2个字符!');

theform.username.focus();

return (false);

}

if (theform.username.value.length > 20){



alert('你的用户名请不要大于20个字符!');

theform.username.focus();

return (false);

}



if (theform.password.value=="") {

alert('请输入密码!');

theform.password.focus();

return false;

}

}