Make sure your brake fluid level is well above the minimum mark, the clutch is fed from a pipe that comes from the right hand side of the reservoir, about half way up the bottle. If it is then you can have a go at bleeding. On the top of your gearbox, just underneath the linkage, is the slave cylinder. On the nearside of the cylinder is a bleed nipple, connect your bleed kit, undo the nipple and push the clutch pedal to the floor and then pull back up, repeat until there are no bubbles in the fluid.
If this doesn't work then its one of the cylinders