HTC magic logging problem

[nushtiu123]

hi every one.

my htc magic was switched off 2 days due to flat battery.

when i switched back on it asked for my google account that i have created when i bought the phone and i couldnt remember it. so i made a new 1 for now..

now i found my old user name n password but i dont know how to switch over between accounts.

i really need this as i have all my contact on my old account

or maybe there are other alternatives of getting my contacts back from my old account

PLZ help

thanks