JavaScript DHTML/Event onMethod/onSubmit
onsubmit action
<html>
<head>
<script type="text/javascript">
function confirmAction() {
return confirm("Do you really want to do this?")
}
</script>
</head>
<body>
<form action="" onsubmit="return confirmAction()" method="post">
<textarea name="comments" rows="6" cols="46"></textarea>
<input type="submit" value="Submit" />
</form>
</body>
</html>
"onSubmit" Example
<html>
<body>
<form name="form1"
method="post"
action=""
onsubmit="alert("The form is being submitted")">
<input type="text" name="textfield">
<input type="submit" value="Submit">
</form>
</body>
</html>
Validate form in onsumbit function
<html>
<head>
<title>Try/Catch</title>
</head>
<body>
<form name="formexample" id="formexample" action="#">
<div id="valueDiv">Enter a Number Between 1 and 100: <input id="num" name="num"></div>
<div><input id="submit" type="submit"></div>
</form>
<script type="text/javascript">
function checkValid() {
try {
var numField = document.forms[0]["num"];
if (isNaN(numField.value)) {
throw "Not a number";
}
if ((numField.value > 100) || (numField.value < 1)) {
numField.style.background = "#FF0000";
return false;
}
else {
numField.style.background = "#FFFFFF";
return true;
}
} catch(errorObject) {
document.write(errorObject);
document.write("<BR>");
} finally {
document.write("finally.");
}
}
function init() {
document.forms[0].onsubmit = function() { return checkValid() };
}
window.onload = init;
</script>
</body>
</html>