why do I get [ too many output arguments] in app designer while the same same code is okay if we use command window to execute it?

Hello every one. I'm doing an app to facilitate getting steam properties by defining temperature. when I run the app and execute the bush-button an error rises ( Too many output arguments.) because of this code

    SS=spline(TS,sf,T);

However, If I click right mouse and select (Evaluate selection in command window), the code will be generated normally and a value of SS will be assigned !!! please note that similar codes like

 hfo=spline(TS,hf,T);
hgo=spline(TS,hg,T);
hfgo=spline(TS,hfg,T);

have executed normally as expected. A file named Saturated.mat has given to you, it contains all the column vector used in these codes except for T, you can put it manually withen the range of [5:373]. Thank you for help :)

[Geoff Hayes]

Moad - are you sure that you haven't defined spline elsewhere in your GUI? Perhaps you have defined a variable as spline or another function with the same name that is conflicting with the spline that you want to call.