javascript判断多个文本框都不能为空的函数小事例
function FunCheck()
     {
        //不为空的文本框的ＩＤ
        if (!CheckFields("txtID,corpID,txtCar,weight,txtTime"))
        {
          alert("****不能为空");
          return;
        }
}

function CheckFields(txtChecks)
 {
   var oArray = txtChecks.split(",");
   for (var i=0;i<oArray.length;i++)
   {
     if (document.getElementById(oArray[i]).value.replace(/\s/g,"") == "")
      {
        try { document.getElementById(oArray[i]).focus(); }
        catch (e) {}
        event.returnValue = false;
        return false;
      }
   }
    return true;
}

//比较两文本框中数字大小

function (ID1,ID2)
{
     if (!(Number(document.getElementById("ID1").value) > Number(document.getElementById("ID2").value)))
    {
       alert("毛重一定得大于皮重!");
       event.returnValue = false;
   }
 }