Complete the sentences with the correct form of the verb

IV.    Complete the sentences with the correct form of the verb.
1.     If we win the money, we (buy)                 a new house. 
2.     We (go)                 on holiday if there is time .
3.     If we (need)             some help, we'll ask. 
4.     She (not write)                 to you if she leaves. 
5.     If Harry stays with his grandparents, Sally (not be)                 happy.
6.     We (do)                 this for you if you want.