c# - call a method in code-behind from client side script -

i'm using asp.net.

i want update part of page (not whole page) without sending page request server. want in client side.

for this, think should use ajax , javascript.

i've created handler page: handler.ashx

i send request , response in plain text:

javascript

  xmlhttprequest.open("get", url); //applyupdate function response in client side.   xmlhttprequest.onreadystate = applyupdate;    xmlhttprequest.send(null); 

code on handler.ashx

response.write("plain text response"); 

now in applyupdate function can use plain text , show in client browser.

but problem this:

i have placeholder1 control in asp.net:

<asp:placeholder id="placeholder1" runat="server"></asp:placeholder> 

how can assign plain text (the response !) label control , add label placeholder1 control !? mean how can use these codes in client side:

label lb1 = new lable(); lb1.text = plaintext; placeholder1.controls.add(lb1); 

these codes in c# (code-behind) how can use such these codes? cannot same thing javascript codes !

excuse bad explanation.

i'll appreciate help.

create element in javascript using response text , append placeholder. if placeholder used explicitly label, can remove , append parent.

this how create element: https://developer.mozilla.org/en-us/docs/dom/document.createelement