Hi rtlm,
It depends on the kite you have, can you tell us a brand name or even model? I'm thinking if it is a 5m and 2 line, it is likely to be a Wipika Classic or earlt Wipika Freeair or maybe a Naish 3.5 (With the hawaiian turtle or pirate logo in the middle of the canopy.
These assumptions are based on the premise that it may be an inflateable kite, if it is a foil kite, that changes everything.
For the inflateable kites, they used to use a fixed leash system with a long line connected to a wrist leash. The line from wrist cuff to where it is TIED onto the flying line should be approximately 3m or so from the bar.
If it is a reride system similar to what Waxman is talking about, the side lines should slide through the bar ends and have a knot or stopper ball to prevent the line slipping through the bar. There is usually a small loop under the ball which you can connect a leash to. When you let go of the bar, the line should slide through the bar thus pulling on only one line and flagging the kite.
The old kites of their day were almost all fixed systems with the leash connected up the line by 3 or so metres, so be wary and make sure if you can before you attach a sliding type leash system to a fixed bar as it will lead to your immediate demise

If it is a foil kite, there is little you can do aside fromrun a third line down from the leash to the centre of the trailing edge of the klite and leave it a bit slack when flying.
If you are unsure please feel free to call me and I can talk you through it or sort it out for you over the phone. 0433 982 696
Cheers,
DM