Next / Previous / Contents / TCC Help System / NM Tech homepage

16. Event attributes

You can set up your document to run a script when various events occur, such as mouse clicks or keys struck on the keyboard. To do this, attach one of these intrinsic event attributes to an element; the value of the attribute is an expression in your scripting language that can handle that event.

To use these attributes, you must declare the scripting language in a meta element inside the page's head element. Here is the general form of this declaration:

  <meta http=equiv='Content-Script-Type' content='T'/>

where T is the MIME type of the scripting language. For example, the MIME type of JavaScript is content='text/javascript'. See Section 6.7, “MIME types: Defining a resource's format”.

Here are the intrinsic event attributes, and the things that can happen to an element with that attribute that will cause the script to be run.

onblur When an element loses focus. See the onfocus event below for a discussion of focus. We're not talking about actual blurriness here; it's just a play on words. If your eyes lose focus, what you see is blurry, right?
onchange When a control on a form changes its value. To be precise, this happens only when the user moves focus onto the control, changes the value of an input, textarea, or select element, and then moves focus out of the control. See Section 14, “Forms: The form element”.
onclick When the user clicks the mouse button over the element.
ondblclick When the user double-clicks the mouse on the element.
onfocus At any given time, some element is said to have focus; this means that any keyboard input from the user is sent to that element. The onfocus event on an element happens when the focus is moved to that element. This can happen due to use of the tab key, or because the user clicked on it.
onkeydown When a user presses a key; applies to the element with focus. See onfocus for a discussion of focus.
onkeypress When a user presses and then releases a key on the keyboard; applies to the element that has focus. See onfocus, above, for a discussion of focus.
onkeyup When a user releases a key after pressing it. Compare onkeydown and onkeypress.
onload When a body element has finished loading.
onmousedown When the mouse button is depressed over the element.
onmousemove When the mouse is moved within an element. Not every position will be reported; the faster the mouse is moved, the fewer onmousemove events will be generated.
onmouseout When the mouse is moved out of an element.
onmouseover When the mouse is moved onto the element.
onmouseup When the mouse button is released over the element.
onreset When a user clicks on the reset button of a form; see Section 14, “Forms: The form element”.
onselect When a user selects some text, as in a textarea element or an input text field. See Section 14, “Forms: The form element”.
onsubmit When a user submits a form; see Section 14, “Forms: The form element”.
onunload When a body element has been removed from a browser window.