20pin+4pin PSU incompatible with 24pin power connector on mobo?

[davidstone28]

I've got a Silverstone 30NF PSU but it has a 20pin ATX power connector (with separate) 4pin power connector.

Unfortunately, my motherboard (Asus A8N Premium) has a 24 pin ATX connector on the motherboard (plus 4 pin connector near the CPU).

Does this mean my PSU is incompatible or can I get away with using some sort of adaptor? If an adaptor is possible, where can I get one from?

Thanks

[BUFF]

http://www.kustom.co.uk/acatalog/info_1908.html