change key

The fact is that the first note in the measure is in the F key and that the folowing notes in that same measure have to be in the G key. When I put the G key on the second note it jumps to the measure before and the first note whitch has to be in F key is also put in G key. I worked around to let the measure in F key and kept the folowing notes that had to be in G key in F key. The result is not nice because theze notes ar far above the system. Is there an other solution?
Any way thanks to Hans for his answer to my earlier request about the cadenza