exec hanging browser

Hello, I am trying to call a build script from a webpage. I found that none of the PHP exec'ing calls would allow me to leave a call in the background and so my browser timed out and the build never worked. So, I wrapped a DOS batch file around the call, using the "start" command to specify how the underlying call should be made. (I "start" a TCL interpreter and give it the build script) Now I have a build.bat that when run from the command line returns immeadiately....but exec'ing or system'ing this script from within a PHP file still hangs the browser. Is this a security issue with PHP? How do you insure that calling long running programs do not hang the browser? Any ideas appreciated, Christopher -- Realisant mon espoir, je me lance vers la gloire. Christopher Hahn (chahn@iwanna.job)