There is no double  variable in midp1 or even midp2.

But if u need to do this i think you should deal with the number as string and
use the substring fuction and calculate your number and then you conact it
again.

We used two integer values the first one was the int  value the second
was the floating point value. My understanding from the hotspot team is
that two ints is about as much processor time as using doubles anyway.