DEMO

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>

<body>
<?php
if(isset($_REQUEST['submit']))
{
		$to1 = $_REQUEST['to'];
		$from = $_REQUEST['from'];
		$sub = $_REQUEST['sub'];
		$msg = $_REQUEST['msg'];
	//$to = "abc@gmail.com";
	//$sub = "Demo-PHP";
	//$msg = "Hello...........";
	//$from ="xyz@yahoo.com";
	mail($to1,$sub,$msg,$from);
	echo "<script type=application/javascript>alert('Message is send !!!');</script>";
}
?>
<form method="post">
<table>
<tr>
<td>To</td>
<td><input type="email" name="to"  /></td>
</tr>
<tr>
<td>Subject</td>
<td><input type="text" name="sub"/></td>
</tr>
<tr>
<td>From</td>
<td><input type="text" name="from" /></td>
</tr>
<tr>
<td>msg</td>
<td><input type="text" name="msg" /></td>
</tr>
<tr>
<td>
<input type="submit" name="submit" value="Send" />
</td>
</tr>
</table>
</form>
</body>
</html>