can't connect to servers

whenever i open HL i activate ESF...but when i get to the list of servers and try to join it says eomthing like "cannot join ESF custom game until the custom game is installed"...well i do have it installed. can anyone help?

do you have alpha or the beta activated? if the background is the old buu one its alpha but if the letters are white and the backroung is blue and has some dbz characters its beta

thanks, i think that was the problem