The data book on this subject has led me to confuse myself (again).
The point is as follows.
configuration of the A-D is as follows
ADCON1 equ b'00000100'
this implies that RA0 and RA1 are analouge inputs and Vref is Vdd
problem comes here RA3 is also analouge input.

RA3 is required as digital output and its Tris flag is set to 0 therefore a
digital output can be sent refering to THE BOOK fig 5-1 the hardware implies
that a digital input is not possable during a A-D conversion no problem, but
a digital output seems possable and after trying this it appears to work.
However the port info changes on the basis of read modify write surely at
this point the data on the digital input is unstable due to being analouge
will this cause a problem with code or can the RA3 be leagaly used as digital
output when ADCON1 is set as above ?
Can sombody clarify this dilema

Thanks Steve.....