Hello both, and many thanks for your responses. I think I didn't give enough information in my original question, as I have had a problem with accidentally having two apple ID's, one of which is now a defunct email address that I can no longer access. Apple told me to create a new email account and an Apple ID with that account, specifically for iTunes on my iPad, which would then allow me to update my existing apps on the iPad. .......and to keep my other Apple ID for everything else ( iTunes on iMac , iCloud, etc.) I have done this. But the newly created ID on the iPad iTunes isn't working. I have now scheduled a call from apple support to help me sort this out.
Many thanks for your time, and if I get a solution to this other than repurchasing the apps I will post it ...