Hi Wither and Miguel,
Thanks for the replies they were both very useful and should help me solve the problem.
p.s. Miguel as I mentioned, I did do a search, but couldn't find the answer, it's not easy when you join a new forum, you try to find where to look but sometimes get it wrong even when you do a search - whereas forums I am used to I can search and find the answer straight away - its the value of being a veteran in those forums. . Anyway just wanted to reiterate that I do always search before I ask, as I previously mentioned.