Any thoughts on how to achieve the following:

IF: "@" contained in column A then calculate running total of values in column B and display results in column C
IF: "<>@" contained in column A then calculate running total of values in column B and display results in column D

----a------b--------c---------d
1 atl
2 @phi-"-300"---"-300"
3 @phi
4 @phi
5 @stl-"-375"---"-675"
6 @stl
7 @stl
8 mon-"106"----------------"-106"
9 mon
10 mon
11 fla--"-300"---------------"194"
12 fla
13 fla