Hi everyone..

I created this code that i think will be of big value for people working with mobile numbers in South Africa.

I created regular expressions to validate it.

On your page just include the following reference

using System.Text.RegularExpressions;

then i created the following two methods.

This one will strip all non Numeric characters from the string you pass in and then convert it to international format...

public static string StripNumber(string p_Number)
        {
            try
            {
                string cleanNumber = "";
                //Strip all the invalid chars.
                for (int inum = 0; inum < p_Number.Length; inum++)
                {
                    try
                    {
                        if (Convert.ToInt16(p_Number.Substring(inum, 1)) >= 0 &&
                                Convert.ToInt16(p_Number.Substring(inum, 1)) <= 9)
                        {
                            cleanNumber += p_Number.Substring(inum, 1);
                        }

                    }
                    catch
                    {

                    }

                }
                //make sure that the number gets converted to international Number format excluding +
                if (cleanNumber.StartsWith("0"))
                {
                    return "27" + cleanNumber.Substring(1, cleanNumber.Length - 1);

                }
                else if (cleanNumber.StartsWith("27"))
                {
                    return cleanNumber;
                }
                else
                {
                    MessageBox.Show("Please check the validation of this number : " + cleanNumber);
                    return cleanNumber;
                }
            }
            catch (Exception ex)
            {
                return "";
            }
        }

Now here is the big one :-) it takes your number that you pass in, call the stripNumber and then goes to the regular expression part and validates the string

        public static Boolean ValidateNumber(string p_Number)
        {
            try
            {
                //International format as per Email from MTN (RDV created expression) 
                /*
                MTN:    27710,27717,27718,27719,2773,2778,2783
                VC:     27711,27712,27713,27714,27715,27716,2772,2776,2779,2782
                CellC:  2784,2774
                8ta:	2781
                Regular Expression for 07X numbers (International) 277[1-4|6|8-9][0-9]{7}
                Regular Expression for 08X numbers (International) 278[1-4][0-9]{7}
                Regular Expression for 07X numbers (International) 07[1-4|6|8-9][0-9]{7}
                Regular Expression for 08X numbers (International) 08[1-4][0-9]{7}
				  
                 */
                string CleanNumber = StripNumber(p_Number);
                //is it a 07x number International?
                if (Regex.IsMatch(CleanNumber, @"277[1-4|6|8-9][0-9]{7}") == true)
                {
                    return true;
                }
                //Is it a 08X number International?
                if (Regex.IsMatch(CleanNumber, @"278[1-4][0-9]{7}") == true)
                {
                    return true;
                }


                return false;

            }
            catch (Exception ex)
            {

                return false;
            }
            finally
            {

            }


        }