Please try is as below.
$(document).ready(function() {
$("#btn").off('click').on('click', function(){
var name = $("#inputname").val();
var email = $("#inputEmail").val();
var feed = $("#feedback").val();
var send = "InputName=" + name + "&InputEmail=" + email + "&Feedback=" + feed ;
alert(send);
$.ajax({
url:"/Feedback_conx.php",
type:"POST",
data:send,
success: function(data1){
$("#disp").html(data1);
}
})
});
});