Trouble on "apex.submit"

Hello everybody,

I'm new to Apex but I have to maintain an already existing apex application. My problem is, that a page is reloading itself in a loop because "apex.submit('P0_OS_USER');" does not seem to reload the same page with the current value of 'P0_OS_USER''. Can you give me some advice?

This Apex.Submit is embedded in "Function an Global Variable Declaration" of Java Script  Body:

function transfer(l_userdomain,l_user,l_host)
  {
document.getElementById('P0_OS_USER').readOnly = "true";
document.getElementById('P0_OS_USER').style.display="none";
if(document.getElementById('P0_OS_USER').value != l_user)