The problem is that I am supposed to calculate predicted possibilities and while I can read the normal regression I CANNOT read (I am ashamed to say) the regression when you have the agegrps split up into 3. I can't relate the coefficients to 'con' and especially how to read the Iagegrps_2 which is omitted.
Ok the coefficient on agegrp_1, for example, is the effect of being in agegrp_1 relative to being in the omitted group, in this case _2. (It has to be omitted to avoid multicollinearity. Alternately you could omit the constant by adding noconstant in the command. If you do this the interpretation of the coefficients will be slightly different) So in your example, age grp 1 is insignificant, while agegrp3 is significant at about 2%.
To predict expected values of the dependent variable you should just be able to use the predict command with appropriate options--check the manual for this.
I really think you want to split agegrps into 3 separate variables. You can do this by:
replace agegrp1=1 if agegrps==1 (I forget the proper syntax for "else" in STATA but you get the point)
replace agegrp2=1 if agegrps==2
replace agegrp3=1 if agegrps==3
Then you run:
logit con sx agegrp1 agegrp3
Then predict. The predict command would do this but if you want to do it manually you can just take the data for one observation and put it in the estimated equation--you'll include both agegrp1 and agegrp3 since it'll just zero out if eith value is 0, and if both are the effect is captured in the constant.
I'm happy to keep this up, but it seems like you're unclear on what exactly a logit regression will tell you, why you put certain variables in, etc. I'd suggest you read up on the basics of linear regression before worrying too much about logit--the principles of multicollinearity, dummy variables, predicted values, etc will translate well.