JavaScript Events

Traditional DOM event handlers

• Use onclick() to send an event when the element is clicked.
• Use onfocus() to send an event when an input is selected.
• Use onblur() to send an event when an input loses focus.
• Use onmouseover() to send an event when the mouse moves over an element.
• Use onmouseleave() to send an event when the mouse moves off of an element.

Change the element class to change it's look

• Use elem.classList.add( "class1", "class2", "class3" ); to add classes to the HTML element.

Validate forms

function validateForm( form ) {
if(form.elements[1].value == "1") {

alert( "Input must have a value" );
form.elements[1].focus();
return false;
}
return true;
}