Trying to understand code

[runnerpaul]

Could somebody please explain what  the below code means?

if(!mb_ereg("^[0-9)(xX -]{7,20}$",$value))

 

I just understand it. It comes from the following:

           if(mb_eregi("phone",$field) 
              or mb_eregi("fax",$field))
           {
              if(!mb_ereg("^[0-9)(xX -]{7,20}$",$value))
              {
                 $errors[] = "$value is not a valid  
                              phone number. ";
              }
           }

 

Cheers

Paul

[.josh]

mb_ereg

 

basically that code says:

 

if the value of $field contains "phone" or "fax" then...

...if the value of $value does NOT have between 7 and 20 of only these characters: 0-9)(xX -

.... then add that error message to the $errors array