Are they evergreen or deciduous Azaleas? Exactly how are they turning yellow? Any chance of a picture or two?

And is your soil acidic or alkaline?

If this is the first time they've looked yellow, likely its just autumn - azaleas are deciduous.

cheers guys iam a new hand at gardening although loveing it ? iam finding it quite diffi'cult so your help is much appreciated

Hopefully your azaleas looked perfectly healthy up until recently... if they didn't, then its not just autumn.

yes they l ooked fineits only happened the last few weeks