Use this function to seperate a part of the script code as a header. Script code inside a header seperation is processed only once. It reduces the cpu usage. It make sense to insert script code into a header which is normaly processed once by the application. For example the definition of a variable is processed only once, so insert this kind of script code into a header.

Example:

#Header
 %LCD.LoadBitmap(lcd.bmp,0,0,XOR)
#EndHeader

The loadbitmap function call loads a bitmap into graphic ram of lcd. In this case the function call draws a background image on the lcd. It makes sense to insert the function call into a header, because the drawing of a background is needed only once.