Ajax 提交和验证

//////////////验证编号是否存在///////////////////

function CheckNO()
{
       if($F('txt_HTBH')=="")
       { 
              $('msginfo').innerHTML="<span class='style1'>発注NO 为空</span>";
              new Field.focus("TxtNO");
              return false;
       }
       else
       {
            searchSales();   
            if ($('err').innerHTML=="true")
            {
                return false;
            }
       }
}
//提交
function searchSales()
{       
var txtno = $F('txt_HTBH');             
var url = 'Check.aspx';       
var pars = 'txt_HTBH=' + txtno;     
    var myAjax = new Ajax.Request(url,{method:'get',parameters:pars,onLoading:loading,onComplete:ShowResult});
}
function ShowResult(Result)
{
    if (Result.responseText.trim()=="error")
    {
        $('msginfo').innerHTML="<span class='style1'>沒有數據</span>";
        $('err').innerHTML="";
        new Field.focus("txt_HTBH");
    }
    else
    {  
        var i;
        var a=Result.responseText.trim();
        a=a.toString();   

/////////////分割返回的字符传 并且显示在(Select 里)/////////////
        for(i=0;i<a.split(",").length;i++)
        {
            $('drp_CPBH').options[$('drp_CPBH').length] = new Option(a.split(",")[i],a.split(",")[i]);
        }

/////////////////////////////////////
        $('msginfo').style.display="none";   //<div id='msginfo'></div>
        $('err').innerHTML="";     //<div id='err'></div>
    }
    $('loading').style.display="none";
    return false;
}
function loading()
{
   $('loading').innerHTML="数据处理中,请稍后.";   //<div id='loading'></div>
}