My husband walked out on me he was pretending to go to work but was seeing some one else.the house is in my name and I have been paying al the bills for the last four years because he has no job now he want me to give him half of every thing he says he is entitled.

Depending on where you live, yes, he may be entitled, whose name is on deed ?

Was house bought, before or after marriage

Where do you live?

Tell him to take you to court and you will agree to what the Judge says. The house being in your name and you paying the bills take proof for the Judge to rule more in your favor. He may not get 50/50 but he could get a portion. Tell him there is no use in him discussing this since you will do as the Judge rules. Until then he is wasting his breath. In the meantime Keep a list of everything he takes or took out of the house.

File for divorce and get a lawyer.
Gather all your papers and proofs of what you paid.
A lot depends on when the house was bought and what state you live in.
Don't just wait to see what he does next.

Laws vary by area, so its possible. As the others have advised, hire an attorney and file for divorce.

Also it is going to make a difference as to how the house was acquired. If it was purchased before or during the marriage and if the judge rules on it being separate property or community property.