HTML 4.0 Event Attributes

New to HTML 4.0 is the ability to let HTML events trigger actions in the browser, like starting a JavaScript when a user clicks on an HTML element. Below is a list of attributes that can be inserted into HTML tags to define event actions.

Window Events

Only valid in body and frameset elements.

Attribute	Value	Description
onload	script	Script to be run when a document loads
onunload	script	Script to be run when a document unloads

Form Element Events

Only valid in form elements.

Attribute	Value	Description
onchange	script	Script to be run when the element changes
onsubmit	script	Script to be run when the form is submitted
onreset	script	Script to be run when the form is reset
onselect	script	Script to be run when the element is selected
onblur	script	Script to be run when the element loses focus
onfocus	script	Script to be run when the element gets focus

Keyboard Events

Not valid in base, bdo, br, frame, frameset, head, html, iframe, meta, param, script, style, and title elements.

Attribute	Value	Description
onkeydown	script	What to do when key is pressed
onkeypress	script	What to do when key is pressed and released
onkeyup	script	What to do when key is released

Mouse Events

Not valid in base, bdo, br, frame, frameset, head, html, iframe, meta, param, script, style, title elements.

Attribute	Value	Description
onclick	script	What to do on a mouse click
ondblclick	script	What to do on a mouse double-click
onmousedown	script	What to do when mouse button is pressed
onmousemove	script	What to do when mouse pointer moves
onmouseout	script	What to do when mouse pointer moves out of an element
onmouseover	script	What to do when mouse pointer moves over an element
onmouseup	script	What to do when mouse button is released

Attribute definitions

onload = script [CT]: The onload event occurs when the user agent finishes loading a window or all frames within a FRAMESET. This attribute may be used with BODY and FRAMESET elements.
onunload = script [CT]: The onunload event occurs when the user agent removes a document from a window or frame. This attribute may be used with BODY and FRAMESET elements.
onclick = script [CT]: The onclick event occurs when the pointing device button is clicked over an element. This attribute may be used with most elements.
ondblclick = script [CT]: The ondblclick event occurs when the pointing device button is double clicked over an element. This attribute may be used with most elements.
onmousedown = script [CT]: The onmousedown event occurs when the pointing device button is pressed over an element. This attribute may be used with most elements.
onmouseup = script [CT]: The onmouseup event occurs when the pointing device button is released over an element. This attribute may be used with most elements.
onmouseover = script [CT]: The onmouseover event occurs when the pointing device is moved onto an element. This attribute may be used with most elements.
onmousemove = script [CT]: The onmousemove event occurs when the pointing device is moved while it is over an element. This attribute may be used with most elements.
onmouseout = script [CT]: The onmouseout event occurs when the pointing device is moved away from an element. This attribute may be used with most elements.
onfocus = script [CT]: The onfocus event occurs when an element receives focus either by the pointing device or by tabbing navigation. This attribute may be used with the following elements: A, AREA, LABEL, INPUT, SELECT, TEXTAREA, and BUTTON.
onblur = script [CT]: The onblur event occurs when an element loses focus either by the pointing device or by tabbing navigation. It may be used with the same elements as onfocus.
onkeypress = script [CT]: The onkeypress event occurs when a key is pressed and released over an element. This attribute may be used with most elements.
onkeydown = script [CT]: The onkeydown event occurs when a key is pressed down over an element. This attribute may be used with most elements.
onkeyup = script [CT]: The onkeyup event occurs when a key is released over an element. This attribute may be used with most elements.
onsubmit = script [CT]: The onsubmit event occurs when a form is submitted. It only applies to the FORM element.
onreset = script [CT]: The onreset event occurs when a form is reset. It only applies to the FORM element.
onselect = script [CT]: The onselect event occurs when a user selects some text in a text field. This attribute may be used with the INPUT and TEXTAREA elements.
onchange = script [CT]: The onchange event occurs when a control loses the input focus and its value has been modified since gaining focus. This attribute applies to the following elements: INPUT, SELECT, and TEXTAREA.