Echo an iframe with a html src that has a php variable

[Main Man]

I have a problem on this code

<iframe src="<?php echo $gateway_url; ?>" frameborder="0" scrolling="no"></iframe>

I want to call up the $gateway_url but I am having this error

Parse error: syntax error, unexpected '<'

Can someone help me

[Main Man]

I hope this will show you where i want to achieve

$gateway_url = $url."?ORDERID=".$orderid."&SESSIONID=".$sessionid ;

<iframe src="<?php echo $gateway_url; ?>" frameborder="0" scrolling="no"></iframe>

[koharu]

Maybe try;

<?php
$gateway_url = $url."?ORDERID=".$orderid."&SESSIONID=".$sessionid;
 
echo '<iframe src="{$gateway_url}" frameborder="0" scrolling="no"></iframe>';
?>

Without seeing the rest of your code, debugging is not really possible.