When I use an input dialog with four fields, the opened window to enter the values moves down on the display by itself. With only three fields, everything just works fine.
prompt = {'Enter U(V)','Enter U_{X}(V)','Enter U_R(V)','Enter R(Ω)'};
dlgtitle = 'Values for 3-voltmeter method';
fieldsize = [1 45; 1 45; 1 45; 1 45];
definput = {'20.0','10.659','9.344','100'};
answer = inputdlg(prompt,dlgtitle,fieldsize,definput);
U = str2double(answer{1});
U_X = str2double(answer{2});
U_R = str2double(answer{3});
R = str2double(answer{4});