Sometimes you want to open a browser window of defined parameters. This is done with javascript. Write the following code in the actionscript frame of your fla file (example only):

myButton.onRelease = function () {
         getURL("javascript:openWindow('website.html')");
}

Then write this script in the header of your HTML page which encodes your swf:

<SCRIPT>
<!--
function openWindow(newWindow){
      window.open(newWindow, "myFile", "height=500, width=750, scrollbars=yes, top=0");
}
-->
</SCRIPT>

"newWindow" is the argument holding your html file, which you want to open. You can define of course any height and width or position as you like.