Concatenation of two columns in Oracle

Question

Possible Duplicate:
Oracle SQL, concatenate multiple columns + add text

I need to write a query to that fetches values of two columns by merging it in certain format.

X          Y
-----      -----
10567      1 M
10568      1.5 M
10567      2.5 M

The result should be in the format

  "X - Y"
 1)10567 - 1 M
 2)10568 - 1.5 M

Any help would be really appreciated..