On button click except values of two element and show result

Question

I have total 3 elements

1. TextBox
2. DropDown
3. Button

What I want is... On Button Click It should Take the parameters from TextBox & DropDown and return the data on Button Click

this.html

    <div class="input" div id="Searching"><input type="text" name="Search" id="Search" class="ContextualSearchField" placeholder="Search" size="40" value=""/></div>
    &nbsp;&nbsp;
     <div class="dropdown">
      <button class="dropbtn">Search&#x25BC;</button>
      <div id="myDropdown" class="dropdown-content">
        <a id="Alert" type="button" class="btn btn-lg btn-default" href="#">Alert</a>
        <a id="IR" type="button" class="btn btn-lg btn-default" href="#">Incident Report</a>
        <a id="Site" type="button" class="btn btn-lg btn-default" href="#">Site</a>
        <a id="Devices" type="button" class="btn btn-lg btn-default" href="#">Devices</a>
      </div>
    </div> 
    <button type="submit" onclick="SearchContext()" id="searchbutton">Search Now</button>

this.js

var Search = document.getElementById("Search").value;
alert(Search);
Dropdown = document.getElementById("myDropdown").value;
SearchButton = document.getElementById("searchbutton").value;
var Alert = document.getElementById("Alert").value;
var IR = document.getElementById("IR").value;
var Site = document.getElementById("Site").value;
var Devices = document.getElementById("Devices").value;

I have also created service for them in jquery.services.js

just tell me how to put those parameter on button

Answer 1

Just put an event listener on your button than do your things in this scope.

document.querySelector('.dropbtn').addEventListener('click',function(){
    //do your required things in here. E.g:
    var Site = document.getElementById("Site").value;
    var Devices = document.getElementById("Devices").value;
});

If you want to put them in a element, just add parameter to element. E.g:
<button id="example" lang="tr" user-id="15" target="Search">Click me</button>
and for take this parameters from JS, do like this with using HTML element function getAttribute():

var lang    = document.getElementById('example').getAttribute('lang');
var user_id = document.getElementById('example').getAttribute('user-id');