auto incrementing->Updating values in two related tables :Help!

hi there,
i am new to sql server database.i am doing small projects rightnow using asp.net and sql to create webpages (very basic webpages)
My problem is:
Problem :

i have two tables ....table 1 and table 2.
Table 1 has following fields: studentid,student name,student address.
Table 2 has following fields:studentid and course .
table1 student id is the primary key refrencing table 2 student id.
Now i delete a record in table 1 which will in turn also get deleted intable 2 . so for eg if i have three records 1 ,2 and 3 ...then idelete 2 in table 1 ...i will have 1 and 3 in both table 1 and table2...now i want 3 to become 2 in both table 1 and table 2...so that idont have empty space between two student id's 1 and 3. so this is myproblem...if any one can help me out with suggestions pleasedo.
thank you all......
ahmed_ind
if you want my advice ... this is not a good solution or methodto follow .... you should not really care about the space ...once you create ID for a record and delete it, you should notreally care about it to have stabled data not to have confliced IDs.
if your concerns about the ID number that you will reach in 1 year ..you can avoid that when you create the ID columns and assign the datatype that has the range for what you know it will enough for you...... if i were you i will not bother myself with what are youlooking for.
By the way this is my idea from my experience and what database expertsthink..... but if some one has different opinion and beleive there isa better technique ... you can advise !!
|||hi fadil.....thanx for u r suggestion.
i wanted to have automation of operation at the background ; i.e. in the database (sql ) ...so i used identity function toauto-increment values of student id by one ....then i wanted to deleteby performing auto-decrement function.....so thats how i camewith the idea, i jus wanted to learn tough things...ok any way thanxagain for ur suggestion and if u have any way of solution for myquestion please do reply..thank u..
ahmed
|||look at this case and see what i mean
ID Name
1 Ahmed
2 John
3 Ali

if you deleted 'Ali' the decrement would be ok as it is the last one on the list but if you delete 'Ahmed' you will loose the primar key integritiy for John and Ali as they will be 1 and 2.....i beleive this is not a good methodlogy to do... you might injure your data !!|||hi fadil,
i get u...i understand what umean...ok then my logic is not a good one then...may be i have to trysomething else than auto decrementing.....
thanxanyway for the suggestions : i will take them and follow them now andin my future...

............ahmed