html focus on input code example

Example 1: html prevent focus on input

<input type="text" id="yourID" value="test" readonly="readonly" /> 

You can change it in javascript with : 

document.getElementById("yourID").readOnly = false; //This enables the possibility to focus

Example 2: focus js

focusMethod = function getFocus() {           
  document.getElementById("myTextField").focus();
}

Example 3: focus js

<input type="text" id="myTextField" value="Text field.">
<p></p>
<button type="button" onclick="focusMethod()">Click me to focus on the text field!</button>