Versuchs mal so:

Code:
<img src="images/pfeil.gif" border="0" alt="">&nbsp;<a href="betau.php" target="onClick='window.open("betau.php", "Auto-Surf","fullscreen,menubar=no,locationbar=no,resizable=yes,status=no,s
crollbars=yes")'">Auto-Surf starten</a>