let's say i wanted to invest $2500 in a company and didn't care how many shares it would pick up...assuming i'm doing this through an online broker, how do i specify i want to buy $2500 worth without having to put in an amount of shares?

please email me your responses, as i check this board about once or twice a week now that i'm home on a slow modem. :-(
psu_asskicker@hotmail.com
thanks tons!