js验证textbox输入的值

function CheckQuery()
{ 
      if(BlankInBatchEdit.txtUNIT_PRICE.value == "") 
            {    
                  alert("请填写[单价]！"); 
                  BlankInBatchEdit.txtUNIT_PRICE.focus(); 
                  return false; 
            } 
     if(isNaN(BlankInBatchEdit.txtUNIT_PRICE.value)) 
            { 
                    alert("[单价]应该是数字！"); 
                    BlankInBatchEdit.txtUNIT_PRICE.focus();
                    return false;
             } 
       if(BlankInBatchEdit.txtUNIT_PRICE.value>=100000000) 
             { 
                     alert("[单价]超出范围！"); 
                     BlankInBatchEdit.txtUNIT_PRICE.focus(); 
                     return false; 
              } 
        if(BlankInBatchEdit.txtDESCRIPTION.value.length >200) 
              { 
                       alert("[描述]长度超出范围!");
                       BlankInBatchEdit.txtDESCRIPTION.focus(); 
                       return false; 
               }


///////////////////////////////////////////////////////
//客户端验证
    btns.btnSave.Attributes["onclick"] = "return CheckQuery();";