function document.onkeydown()
{ 
    var e=event.srcElement; 
    if (event.keyCode==13) 
    { 
        document.getElementById("btnSearch" ).focus(); 
        return true ; 
    } 
}
function Clear()
{
    if(document.getElementById("txtValue").value=="保险杠" && document.getElementById("txtState").value=="0")
    {
         document.getElementById("txtValue").value="";
         document.getElementById("txtState").value="1";
    }
}
function Find()
{    
    var b=document.getElementById("ddlBrand").value;
    var v=document.getElementById("txtValue").value;
    if(b=="")
    {
        alert("请选择您的汽车品牌!");
        return false;
    }
    else
    {
        if(v=="")
        {
            v="保险杠";
        }
        var f=document.getElementById("ddlFactroy").value;
        var s=document.getElementById("ddlSeries").value;
        window.location.href="/search.aspx?b="+b+"&f="+f+"&s="+s+"&v="+ encodeURIComponent(v);
    }
}