whats wrong with my A/c? Options

[daazndood]

hey guys im kinda a car n00b so and my A/C is no longer working (and its 100 degrees in stockton just great huh?)

so when i turn it on the lowest setting, its cold for maybe like 2 minutes but then it stops blowing cold air and its just blowing normal air. i try to turn it up a little higher but then alot of crap like dust and stuff flys out of the vents and into my eye balls. not the best thing to happen while driving.

someone told me to change some kinda pump and someone else told me to pour in more liquid(forgot what it was called).

i thought it'd be alot more useful if i asked you guys instead.