What is the expansion of SIM CARD?

my iphone 3gs doesnt not detect sim card and carrier, i'm so stressed out. i dont wannt to waste my money on another phone now.!!!!

• My ipone was working perfectly fine before,then this foolish idea came to my mind “what if I update it to ios 5?”. Then i upgraded my iphone from 4.2.1(which was already jailbreaked) to ios 5 from itune. After a successful upgrade,( I don’t have wifi around my area so I couldnt use internet to activate my sim card, so from mobile I choose the option to use itunes), i couldn't go any further because my iphone did not detect the sim card and in itunes it was saying "cannot detect sim card which you are trying to activate, insert a sim card". then i wondered, must be i need to jailbreak ios 5. Then i googled and tried to jailbreak ios 5 untethered using redsn0w. it was successful i guess but then once after finishing the jailbreak, it had to restart, then my iphone would not open. it just hanged while loading or opening. i tried a lot but still would not start, just hanged at the loading screen. even waited for 12 hours, still the same. then i decided to restore from the itune back to its previous version. i restored it from the backup. but again i could not go any further, it just kept saying that "could not detect sim card which you are trying to activate, insert a sim card." i tried to jail breaking again but this time it didnt work. now i thought i'm ruined, damn, then i went to the repair shop of iphone. they installed the ios 4.1, jailbreaked working fine, but, now, the problem is that, my iphone doesnt detect the sim card nor the carrier. now when i open the sim card using pin, it doesnt even notify "no sim card inserted". my iphone doesnt say anything whethere i open the sim card or keep a sim card. when i restart my iphone, at the begining it shows searching "at the top left corner"..but then after a while, it says no service and when i open the sim card using a pin, it doesnt notify me saying that " no sim card inserted" or anything. I will get mad. what should i do? repair person was saying "it may be hardware problem". Is it a hardware problem or so

• Answer:

  It's software, coz I got it back working before iOS 5 update, but cannot remember how :/ I have same situation now after trying iOS 5 update. I can get it to boot and show 1 bar without carrier (info shows correctly though), so only phone function is broken..