bootstrap button not working !

Question

i have used only bootstrap classes in the asp textbox and dropdown controler controler and also the button. when i used requiredfieldvalidater and when i executed the page the button is not working as before it was.

 

what could be the reason ?

 

 

links i have used are 

 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/css/bootstrap.min.css"/>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js" type="text/javascript"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js" type="text/javascript"></script>

 

<asp:Button class="btn btn-primary" ID="btnSearch" runat="server" Text="Search" onclick="btnSearch_Click"
               />