Example
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<form name="myform" method="post" action="">
<input name="row_password" type="text" size="40">
<input type="button" class="button" value="Generate" onClick="randomPassword(10);" tabindex="2">
</form>
<script>
function randomPassword(length) {
var chars = "abcdefghijklmnopqrstuvwxyz!@#$%^&*()-+<>ABCDEFGHIJKLMNOP1234567890";
var pass = "";
for (var x = 0; x < length; x++) {
var i = Math.floor(Math.random() * chars.length);
pass += chars.charAt(i);
}
myform.row_password.value = pass;
}
</script>
</body>
</html>