If you are just storing a PIN that needs to be numeric, you should use a text fields with an "ISNUMBER" validation rule to ensure it's always a number. Number fields should only be used if you need to perform math. You can't remove the comma in the actual field -- that's default behavior for a number field.
This is from the Salesforce online help (search for ISNUMBER)
ISNUMBER
Description:
Determines if a text value is a number
and returns TRUE if it is. Otherwise, it returns FALSE.
Use:
ISNUMBER(text) and replace text with the merge field name for the text field.
This validation rule ensures a custom text
field called Bank Account Number is a number
of 10 digits and is not blank.
Tips:
This function returns FALSE for blank values.
The ISNUMBER function is not aware of your locale. For example, ISNUMBER("123,12") and ISNUMBER("1 000") return FALSE even if the user's locale is "French."
Chinese, Japanese, Korean, and special characters including a
space return FALSE.
The ISNUMBER function returns TRUE for scientific formatting such
as "2E2" or "123.123."
This function is available everywhere formulas
exist except formula fields and default values.
Does the value in the field have to support arithmetic operations? If not, just define it as a string.
Hope this helps.
-Rick
actually this field is used for capturing PIN code that can be numeral only.
if data type is changed to string , user can put characters with numbers.
isn't there any other method to control that comma field?
mahi
This is from the Salesforce online help (search for ISNUMBER)
ISNUMBER
This validation rule ensures a custom text field called Bank Account Number is a number of 10 digits and is not blank.
Hope that helps.
Mark