Javascript is very useful for handling HTML events. For example, when mouse moves over the text, the color, font size and weight of the text changes dynamically using javascript scripts.
<script language="javascript">
function mover(p)
{
var elem;
elem = document.getElementById(p);
elem.style.fontWeight = "bold";
elem.style.fontSize = "16px";
elem.style.color = "green";
}
function mout(p)
{
var elem;
elem = document.getElementById(p);
elem.style.fontWeight = "normal";
elem.style.fontSize = "15px";
elem.style.color = "black";
}
</script>
<div id=tt onmouseover="mover('tt');" onmouseout="mout('tt');">
Change text color and font size</div>
The mouse move over event is handled by
In HTML forms, javascript may be used for input data validation via events such as
<form onsubmit="alert('test'); return false;">
<input type=submit value="submit">
</form>
The following code will check the user input, if it is a number, then it will be deleted.
<script language="javascript">
function isNum(args)
{
args = args.toString();
if (args.length == 0) return false;
for (var i = 0; i < args.length; i++)
{
if (args.substring(i,i+1) >= "0" && args.substring(i, i+1) <= "9")
{
return true;
}
}
return false;
}
function formcheck()
{
var a = document.fm.inp.value;
if (isNum(a))
{
a = a.substring(0,a.length-1);
document.fm.inp.value = a;
return;
}
}
</script>
<form name=fm>
<input name="inp" id='inp' autocomplete="off" onkeyup="formcheck()" type="text" style="font-size:19px;width:370px;height:28px" class="SearchNews">
</form>
Window events is another important events. For example, the following event handler "onload" will show an alert window after page loads.
<body onload="alert('test');">
Click here for more window events.