[TYPO3-english] Using IF in TypoScript

[Redvald Hjulstad]

I have a script that creates a image from the pageheader. But I would 
like it to only generate the image if there is a image on the 
mediafield. As it is now it is generating a transparent image if there 
is noe image in the mediafield.

Here is my TS:
lib.image = IMAGE
lib.image {

	file = GIFBUILDER
	file {
		if.isTrue.field = {page:media}
		XY = 569,419
		format = png
		backColor = #e5e5e5
		transparentColor = #e5e5e5
		transparentBackground = 1
		10 = IMAGE
		10 {
        	file.width = 550c
        	file.height = 400c
		file.import=uploads/media/	
		file.import.data = levelmedia: -1,slide
		mask = fileadmin/templates/main/images/mask.png
			
		}
		
				
		}
	}

I have tried to use the if.isTrue.field several places in the script, 
but can not figure out how ot get it right.

red