# 15.3.4.4.6 The Script Before Install Page

## Dialog Box Controls

 Python Package Check(LabTalk Script) Add script to this box to prompt users who are installing user-defined Python fitting functions, of Python packages required to use the fitting function. When an end-user drops the FDF file onto the Origin workspace, the script is executed. The page cannot be empty (Python functions only). If required packages have not been installed, the end-user is prompted to allow package install. If required packages are already installed, the end-user is prompted to add the fitting function to a category. An example script follows. Substitute your required package(s) inside the parentheses and double-quote marks, as needed: [BeforeInstall] if(Python.chk("pandas cv2(opencv-python)") > 1) return 1;//should not install FDF return 0;//proceed