a problem about fir design using dspbuilder

Hi,

I want to design a fir filter with dspbuilder,but the result is not correct,I'm very confused.

The following are the parameter I want to reach:

The source signal is sythesis of a sin signal which frequency is 200HZ and a sin signal which frequency is 5000HZ.I want to design a low filter.so that I want to see only the 200HZ signal after the sounce passed the filter.The sample frequency is 20000HZ.

AP:1db AS:30db

I use the kaiser window with beta=0.5

I will show the whole design with my .mdl file,expect your response as soon as possible!

Thanks for any help. I'm a freshman in filter design.