validation on client side on gridview textbox and dropdown

Question

Hello Sir,

 

I have a girdview, in that i have textbox and dropdownlist.

I want to validate that control on client side with checkbox if checkbox is checked then check the textbox is empty and dropdownlist also.

 

I done that validation but whenever checkbox is checked and textbox not empty then also alert msg is showing..

 

Please help me.

 

the code is :--

on button click.... 

 

function Validate() {

var chkBoxList = document.getElementById('<%=gv_Toppers.ClientID %>');

var chkBoxCount = chkBoxList.getElementsByTagName("input");

for (var i = 0; i <chkBoxCount.length; i++) {

if (chkBoxCount[i].checked) {

var txtMarks = document.getElementById('txtMarks');

var ddlRank = document.getElementById('ddlRank');

if(txtMarks=="" || txtMarks== null)

{

alert("Please Enter Student Marks!!!");

return false;

}

if (ddlRank.value == "0" || ddlRank.value == "Select Rank") {

alert("Please Select Student Rank!!!");

return false;

}

}

}

}