As Sted says check it first, if not:
http://www.amazon.co.uk/Belkin-1-8m-HDDB15-Monitor-Cable/dp/B004RONFDE/ref=sr_1_34?s=computers&ie=UTF8&qid=1370272407&sr=1-34
If you are using a splitter you may need male to female for the main connection (PC to splitter)
http://www.amazon.co.uk/Belkin-HDDB15-Female-Monitor-Extension/dp/B004PY044O/ref=sr_1_2?s=computers&ie=UTF8&qid=1370272491&sr=1-2&keywords=vga+cable+male+to+female
These are decent cables, if you want a bog standard cheap one:
http://www.amazon.co.uk/Monitor-Replacement-SVGA-Cable-Black/dp/B001MQGOLU/ref=sr_1_1?s=computers&ie=UTF8&qid=1370272543&sr=1-1&keywords=vga+cable