Need help Vauxhall Corsa wont start?

My Vauxhall corsa 1.0 R Reg has died on me, it use to start for a little while then it would die on me, now It wont start, I have changed battery and spark plugs, plus added treatment fluid to clean out carb. I've even tried to start it with someone pulling me with their car, Does anyone have any idea what could be wrong so that i can fix the problem.