Your code for the calling window:
Code:
<!DOCTYPE html>
<html>
<head>
<script>
function open_win()
{
window.open("test_3.php?myvar=hello");
}
</script>
</head>
<body>
<form>
<input type="button" value="Open Window" onclick="open_win()">
</form>
</body>
</html>
The window it opens is like this:
PHP Code:
<?php
$bill = $_GET["myvar"];
echo $bill;
?>