c# - Check duplicate user name with client-side validation -

c# - Check duplicate user name with client-side validation -

i have 1 input type , button, used come in username sql database via ajax.

now want accomplish validation checks duplicate names. if duplicate exists error message shown, help regarding this

<div id="div1"> <label>formname</label> <input type="text" id="text1" placeholder="type form name here" class="form-control" /> </div> <div id="div2" style="float: right;"> <input type="button" id="button2" class="btn btn-default" style="" value="save form" /> <input type="button" id="button3" class="btn btn-success" style="" value="add section" /> </div>

this how look:

back end

prepare sql query check duplicates expose on server, perhaps restful api or wcf

front end

add ajax phone call end service hook phone call event, perhaps when user shift focus text box or maybe press check button

c# asp.net validation