FULL SUMMARY OF WHATS HAPPENED:
This is seriously ticking me off, had my brothers iPhone 3GS 4.2.1 for about 2-3 months, was working fine, no problems until today, I was on a call, when I finished, I tried pressing the 'End Call' button, but it didn't work, so I pressed the sleep/wake button to end the call, whatever, didn't think much of it at the time, later on I tried unlocking my phone(slide to unlock, just to clarify
) and the bar went to about half way and went back, so I just locked it, and unlocked it again and it worked slightly better, I got a bit worried so I rebooted my iPhone, didn't make a difference. So later on I get a text, I try to reply to it, as I preview what I've written so far, I realised that none of the text had spaces between them, all joined together, so I attempted to write it out again, no luck, later on I figured out that I have to hold the space button for about half a second for it to actually function, aswell as the rest of the bottom half of my screen, I really do not want to be holding down every button for about a second everytime I want to write something. Any help/tips would be very much appreciated! I havn't actually done much to try to sort it out myself as I don't want to be getting into something I know nothing of, if you know anything about this please reply! this is extremely annoying! 
Thank you guys,
-Deej
This is seriously ticking me off, had my brothers iPhone 3GS 4.2.1 for about 2-3 months, was working fine, no problems until today, I was on a call, when I finished, I tried pressing the 'End Call' button, but it didn't work, so I pressed the sleep/wake button to end the call, whatever, didn't think much of it at the time, later on I tried unlocking my phone(slide to unlock, just to clarify
Thank you guys,
-Deej