Calculation Total/Sum Using Fox Code

My Fox coding is as follows.

data ta type f.

data ztotcost type keyfigure_name.

zvtotcost='vtotcost'

for each zvtotcost.

ta=ta+ztotcost.

endfor.

message i001(/sem/003) with ta.

Note: vtotcost is keyfigure.

as i gave message after loop. It is displaying value of TA Six Times(having 6 records) and final summation value is not displaying.

For each iteration message is displaying? why?

Is there any thing wrong in coding?

tx