Issue with CAS solver function involving passing strings to the variable position.

[Grayhek]

I am writing a program that asks what the user would like to solve for and then pass that into the CAS Solve function. The program look like this:



[code]//Amplitude
export Amplitude()
BEGIN
Local Find,Find_1,variables,Answer;
Local Â,K,τ,ω;

print();
//K=5, Â=0.0355 τ=10 ,ω=3.1415 ,E=.5 ,A=7
A:=0;

CHOOSE(A,"Which Amplitude?","Final","Initial");
if A==1 then
variables:={"Â","K","τ","ω","E","A"};
input({{Find,variables,{56,15,0}},{Â,[0],{10,20,1}},{K,[0],{10,20,2}},{τ,[0],{10,20,3}},{ω,[0],{10,20,4}},{E,[0],{10,20,5}},{A,[0],{10,20,6}}});
Find_1:=variables[Find]; Find:=Find_1;
Answer:=CAS("SOLVE(Â=K*A/(sqrt((1-(τ*ω)^2)^2+(2*τ*ω*E)^2)),Find,1)");
print(Answer);
end;
END;[code]

When I run this it returns "Error: Constant function"
I have tried expr(Find) and also EVAL(Find) but both options failed to work.