Have a look at the 'GREATEST' function:SQL> select greatest(&yourvalue, 0) x
2 from dual
3 /
Enter value for yourvalue: -1
old 1: select greatest(&yourvalue, 0) x
new 1: select greatest(-1, 0) x
X
----------
0
SQL> /
Enter value for yourvalue: 120
old 1: select greatest(&yourvalue, 0) x
new 1: select greatest(120, 0) x
X
----------
120
SQL> /
Enter value for yourvalue: -12.3
old 1: select greatest(&yourvalue, 0) x
new 1: select greatest(-12.3, 0) x
X
----------
0
SQL>

You **could** get the job done with decode (and sign), but I feel that this is more obvious

MHE