my MacBook Pro wont detect my hard drive

Hello everybody i have a massive issue on my macbook pro. if anybody can help me solve this problem i will be VERY great full.

Before i ask you the question here is a list of my macbook's specs:

Model: MacBookPro 13inch Early 2011

CPU: 2.3GHz Dual Core i5

RAM: 10GB of DDR3 @ 1333MHz

HDD: 320GB SATA (my macbook cant detect it when it turns on, this is the hard drive that came with the mac when i bought it)

Graphics: 512MB Intel HD Graphics 3000 inbuilt

OS: Mac OS X Mavericks 10.9.1

Now that you know my specs here is the issue (NOTE: i have had this mac since i bought it in 2011 and it has been working fine untill today when this issue happened.)

My mac was running slowly, so i decided to put my mac onto safe mode. After it went on to safee mode i clicked disk utility and it opened up as usuall. Then i selected my only hard drive and clicked on 'verify' so it verified and then warned me that the HDD needed to be 'repaired' using disk utility. So i clicked on 'ok' and i then clicked on the 'repair' button on disk utility. so it ran for a bit then is froze in the middle of the 'fixing' process. so i clicked 'stop' so i could be able to try this process again, but instead of stopping it froze. so i then turned off my mac so i can restart the computer because it froze on safe mode. So after it turned on it showed the usuall white screen with no logo in it. then i say a picture of a file with a question mark in the middle of it. so i guessed my mac couldnt detect my hard drive. Thats how i came here to these forums so someone can help me solve this issue. By the way i am currently using my friend's mac in order to access these forums.

so please can you help me solve this problem, thanks.