【www.gdgbn.com--jquery】

function chkSignIn(language)
{
 if( chkUserNameForSignIn( $.trim($("#username")[0].value),language ) ){
  if( chkUserPwd( $.trim($("#userpwd")[0].value),language ) ){
   return true;
  }else{
   $("#userpwd").focus();
  }
 }else{
  $("#username").focus();
 }
 return false;
}

function chkUserNameForSignIn( str,language )
{
 if( $.trim(str) == "" ){
  if(language == "EN")
  {
   window.alert( "Please enter your member ID!" );
  }
  else
  {
   window.alert( "请输入您的会员名！" );
  }
  return false;
 }
 return true;
}

function chkUserPwd( str,language )
{
 if( $.trim(str) == "" ){
  if(language == "EN")
  {
   window.alert( "Please enter your password!" );
  }
  else
  {
   window.alert( "请输入您的密码！" );
  }
  return false;
 }
 return true;
}

本文来源：http://www.gdgbn.com/wangyezhizuo/20992/