Question: how to code embedded components

i was to design a GUI using embedded components, i started as shown in the screenshot i uploaded but i had alittle problem trying to code the `evaluate at params` bottton i wanted the botton to return the evaluation of the mathematical expression at the value of the various parameters [delta,gamma,alpha,G,C] into the mathcontainer infront of it i.e evaluating at these points which can be change as new vualues are type in the textfeilds. such as

this is the code i used and it poping out an error message

use DocumentTools in

module()
local f,q,delta,gamma,alpha,G,C;

Do(f=%MathContainer0);
Do(delta=value(%MathContainer1));
Do(gamma=value(%MathContainer2));
Do(alpha=value(%MathContainer3));
Do(G=value(%MathContainer4));
Do(C=value(%MathContainer5));



q:=eval(f,value,delta,gamma,alpha,G,C);
Do(%MathContainer6=q);




end module;
pls i need some one to correct me