If statement formula with multiple condition

hi all,

i am looking some if formula & how to figure it out this problem ;
name--------expected result-------data1
john---------- ok----------------- mark "-"
mark "-"-------- mark "-"-----------mark "-"
mark "-"--------- mark "_"----------george bush

criteria :
1) if col.a contains text and col.c contains mark "-"----result in col.b "ok"
2) if col.a contains "-" and col.c contains "-" ----result in col.b "-"
3) if col.a contains "-" and col.c contains text ----result in col.b "-"

how make it with if statement?

any assistance would greatly appreciated..

john m

cheers

ups, sorry here corrected..

only single column (name column)

name-------expected result ;
text ------- ok
mark "-"----- mark "-"
blank--------blank

criteria :
1) if col.a contains text ----result in col.b "ok"
2) if col.a contains "-" ----result in col.b "-"
3) if col.a contains blank ----result in col.b-- blank

here workbook attached..

if formula problem.xlsxlook at attached pls

thanks, bolulusam...
working well...