the /* ends the execution of the sql query...that why you cant input whatever you want as password
lets say the query that is normaly executed is:
select * from blabla where username=x and password=y .....
by using the sql injection you change the query to
select * from blabla where username=' or 1=1 /*
1=1 is always true so it will select the first entrance in the db as the user(in this and many other cases=the admin)
and thats it,its one of the most simple methods of sql injection
Thats what I thought it was. I usually see it as a "--" (dash dash) but it all makes sense now. Thanks for the clarification.