I may be incorrect, because I am a relative PHP newcomer. However, I don't believe you can use any PHP command to print. Why?
PHP is a Server Side scripting language. It runs on the server before anything is ever sent to your client. Once you view the page on the client, PHP is no longer involved. Therefore, there is no ability to print using PHP.
That said, there are ways to do this in Javascript. Try putting this in your page. I make no guarantees that it will work in every browser:
<SCRIPT LANGUAGE="JavaScript">
<!--
if (window.print)
document.write('<FORM><INPUT TYPE="BUTTON" VALUE="Print this page" onClick="window.print()"><\/FORM>');
//-->
</SCRIPT>
That makes a button that prints the page. If you want a submit button that also prints (which I don't recommend), then simply create a Javascript function that is called when you click a standard (not Submit) button. call the above window.print() function, then call a form.submit() function. That should work, but I strongly recommend you use a separate print button. It can get annoying to have a submitted form ALWAYS print the page!
Now... I'm thinking perhaps you want the next page to print... kind of like a confirmation page. If that's the case, then simply put the appropriate javascript at the end of the page, calling the window.print() function. If you don't want it to prompt the user with the print dialog box, then you have to get a little trickier and access the Windows API, and I'm not going into that, since we're already beyond the scope of this forum.
Try a google search on "Javascript printing" or "VBScript printing."
Good Luck!
