how can i bypass my ford escort van imobaliser?

i have a ford escort van s reg it startes when it feels like it. imobaliser seems to be stopping it from starting at other times i was wondering if there was a way of bypassing the imobaliser the red flashig light fashes when key is taken out and when key is put in the ignition if it is going to start the light will light for about 3to4 seconds and then go out if its not going to start it will not light when ignition is switched on is it not reading the key or is it somthing else can it be bypassed easely .the key has a red chip in it but i dont have the red master key can anyone help thanks