Why my washing machine won't drain?

I have electrolux ewf1087 (bought in Nov 2006) and it won't drain since yesterday, then I tried to open the drainage tube even the drainage hose, I checked the pump was working but there is no water come out.
then I leave the water inside the washing machine overnight, in the morning I check it the water is gone.
then I try to run the washing machine again.. it running until it want to drain then stuck again... :(
does anyone have a tips to handle this kind of problem?
thanks in advance for your help

Regards,
Ferry