Regarding validation of table fields

Hi,

I have created a Table <b>TABLE1</b>.

In that for some fields i need to do validation like below:.

1. For Field <b>FIELD4</b> i need it to Defaulted to '<b>$</b>' whenever an entry is created in this table.

2. For field <b>FIELD6</b> i need to increment every time by 10.

3. For field <b>FIELD7</b> i need to validate with some Z-Table 2-field(s).

I need to do these validations.

How can i do them!

Can anybody solve this issue!

How can i write these validations for above fields in table!

Thanks,

Deep.