MATLAB: How to filter a signal using firlpnorm??

filterSignal Processing Toolbox

'y' is the input white noise and 'g' is the sine wave… h=y+g… how to filter 'h' using firlpnorm??

     Fs = 1000;     t = 0:1/Fs:1;     % 50-Hz sine wave in noise     x = cos(2*pi*50*t)+randn(size(t));     % lowpass filter     B = firlpnorm(22,[0 .15 .4 .5 1],[0 .4 .5 1],[1 1 0 0 0]);     % Filter magnitude response     fvtool(B,1)     % Filter the data     y = filter(B,1,x);