overwriting of <div>

can we use z-index for <td> tag also.....???? because one div is overlaying another <td>

Yes, it can be used for any element as long as you have positioned that element.
http://www.w3schools.com/cssref/pr_pos_z-index.asp

you need to give position:relative for that td

One more thing gurvinder....is there any way that if one div is there of index 2 and one of index 3....when idiv with index 2 is hidden then index of div 3 get enabled automatically

i guess, even if the div with z-index 2 is not hidden, div with z-index 3 will always be enabled regardless, since it will be on top of div with index 2.
Higher index takes more priority and it overlays whatever is beneath with lower z-index

and if index 3 div is hidden.....will the div with index 2 will be enabled automatically

Yes

shukriya.....:P:P

Glad to help. Please respond to your other open questions as well

i want to hide second div whose z-index:2 and enable to first div whose z-index:1  by calling function

function hidestuff(id,toph,main)
{
document.getElementById(main).style.border="none";
document.getElementById(id).style.display="none";
}

it hide second div but doesn't enable first div

thanks in advance

please explain the parameters of this method

which one is div with index 1 and which one is div with index 2

i have two div

one with index 1 and one with index 2........ when i click on one link then i want ke zindex get replaced that is the procedure i want...... so plz explain me with short example

i am not able to solve problem its just like facebook chat ....when chat window get opens then area behind that window become absolute

is it possible for you to share live internet link

www.labbo22.com

username is : contacts@savsoft.co.in
password is sasasa...come there i ll tell you what i want

how should i login? i don't see the link to login

i am able to login, but it says unable to post

ya plz login there again.....actually i have unblocked you... because we were testing so come back..thr?