SaveBitmapToJPEGFile Issue - Badly formed pathname

im trying to use the SaveBitmapToJPEGFile function

when im using a string by its stringname it gives me this error

but when im using the actual string itself it works fine..

for example:

this gives me an error

SaveBitmapToJPEGFile (wagepdf,tempname1, 0, 100);

while tempname1 contains "WageReport 16/02/20 13:50.jpg"

but this works fine

SaveBitmapToJPEGFile (wagepdf,"WageReport 16/02/20 13:50.jpg", 0, 100);

any idea why it doesn't work for me and how can i fix it?

thanks