How to enable or disable a button based on a value in angularjs? -

how enable or disable button according select value? want button disabled once select value changed vaue "xxxx" button enabled.

use ng-disabled directive this:

<div class="form-group">     <label class="control-label"> etat</label>     <select class="form-control" name="singleselect"  ng-model="demande.etat">         <option value="etude">etude</option>         <option value="accepte">accepte</option>         <option value="refus">refus</option>     </select><br> </div> 

and in button markup use this:

<button ng-disabled="demande.etat != 'accepte'">     .... </button>