Question

<script type="text/javascript">
window.onload = init;

function init() { //wait for load and watch for click
    var button = document.getElementById("searchbutton");
    button.onclick = handleButtonClick;
}

function handleButtonClick(e) { //get user input and go to a new url
    var textinput = document.getElementById("searchinput");
    var searchterm = textinput.value;
    window.location.assign("http://google.com/example/" + searchterm)
}
</script>

<form>
    <input type="text" name="search" id="searchinput">  
</form>
<input type="submit" value="Ara" id="searchbutton">

In this code block, it gets user input and go to a new url with user input.

if I move last line into form element it doesn’t working.
But I’m using id to find elements.

Answer 1

Instead of

<input type="submit" value="Ara" id="searchbutton">

use this (MDN docu)

<button type="button" id="searchbutton">Ara</button>

Your button works as a form submit button, so instead of just executing your JavaScript, it also tries to submit the form, which points back to the script itself. By using <button type="button"> you define a mere button without any submitting functionality.

Besides: If you don’t need the surrounding <form> element, why not drop it out of the code?