December 27, 1999 - The blur Event | WebReference

December 27, 1999 - The blur Event

Yehuda Shiran December 27, 1999
The blur Event
Tips: December 1999

Yehuda Shiran, Ph.D.
Doc JavaScript

A blur event occur when a text field loses focus. A field gains focus when the user clicks inside the text box, and the focus is lost when the user clicks outside the box, anywhere on the page. The onBlur event handler executes JavaScript code when a blur event occurs. Take a look at the following form and functions:

function checkInput(element) {
  if (element.value == "")
    alert("Please enter a value!");
// -->
<INPUT TYPE="text" NAME="myField" VALUE="" onBlur="checkInput(this)">

An alert dialog box informs the user that he or she must enter a value in the text box if the box is left empty. The dialog box is displayed only if the user first accesses the field and then exits it without entering any value.