Here is the code:

clear
clc
g = 32.2
row = 0.00238
prompt = {'Enter the UAV weight in lbs:', 'Enter the UAV Max airspeed 
in knots:', 'Enter the UAV Max altitude in feet:','Enter the UAV loss 
of comms in seconds:'};
title = 'Hazard Pattern Dynamic Data';
lines = 1;
answerdynamic = inputdlg(prompt, title, lines);

button=questdlg('Does the UAV contain a parachute?', 'Yes','No');
if strcmp(button, 'Yes');
    prompt = {'What is the parachute Cd?','What is the parachute 
cross sectional area in feet squared?'};
    title = 'Parachute Information';
    lines = 1;
    answerpara = inputdlg(prompt, title, lines);
else
end
WT=answerdynamic{1,1}
VS=answerdynamic{2,1}
ALT=answerdynamic{3,1}
COMM=answerdynamic{4,1}
CD=answerpara{1,1}
CAREA=answerpara{2,1}

Dist=(VS*(0.59209))*COMM
The Problem is computing Dist I get an uknown error in Matlab?  
Anyone ever seen this before?