onfocus Attribute

Where to use the onfocus Attribute

• As Type Script:
  onfocus is declared on the elements: a, area, label, input, textarea, select, button

Description

The onfocus attribute specifies script to be executed when the element gains focus, for example when tabbed to.

See also the onblur attribute.

If you use this attribute (or any attributes of Type Script) the MIME type of the scripting language used should always be provided in a Content-Script-Type HTTP header.

It is good practice not to use these attributes, however, and instead to include external scripts (via script elements) which add any handlers unobtrusively. This makes code more self-contained and also the XHTML is easier to maintain if it doesn't contain any events attributes.

Note: In many browsers, label elements cannot be tabbed to and never receive focus (any focus is merely passed on to the relevant form control) so the script in the onfocus attribute is never executed in these browsers.