<!DOCTYPE html>
<html>
<body>
<input type="text" id="myText" value="Some text.." onselect="myAlertFunction()">
<p>Click the button to select the contents of the text field.</p>
<button type="button" onclick="mySelectFunction()">Select content</button>
<p>The select() method of the HTML DOM Input Text Object selects the contents of the text field. When this happens, the onselect event fires, which will trigger the alert function.</p>
<script>
// Select the contents of a text field with id="myText"
function mySelectFunction() {
document.getElementById("myText").select();
}
// Alert some text when the text in the text field has been selected
function myAlertFunction() {
alert("You selected some text!");
}
</script>
</body>
</html>