Can anyone tell me how to downloasd the software for my motorola mobile so that I xcan get the photos onto my PC?

What is the make and model of your phone?

It's a motorola BC50 - I bought it 2nd hand and didn't get the disk with it for the photos to PC

That model number doesn't show up on their site:
Motorola United States - Support Home Page (click on link "Which phone do I own?")

Navigate that site to see if you can get the software as a download, or else you'll have to buy the software or ask the seller to find the CD for you.