Hello, I am trying to create a validation rule for only numbers to be used in a text field type. I originally was using the number type, but it was generating commas, which I do not want. I have been trying to use the formula (NOT(ISNUMBER(Phone_Extension__c))). It is giving me a message that says the following
Error: Field Phone_Extension__c may not be used in this type of formula
Anyone know what I am doing wrong?
11 answers
Hi Mayra,
Try this
IF( Left(Phone_Extension__c,1) = "x", NOT(ISNUMBER(Right(Phone_Extension__c,LEN(Phone_Extension__c)-1))), IF(ISBLANK(Phone_Extension__c),false,NOT(ISNUMBER(Phone_Extension__c)) ) )
