CRM Phone Number Formatting onChange with Extensions

Format Phone Numbers in CRM

Format (xxx) xxx-xxxx

var oField = event.srcElement;
if (typeof(oField) != "undefined" && oField != null && oField.DataValue != null)
{
    var sTmp = oField.DataValue.replace(/[^0-9]/g, "");
    if(sTmp.length == 10)
    {
        oField.DataValue = "(" + sTmp.substr(0, 3) + ") " + sTmp.substr(3, 3) + "-" + sTmp.substr(6, 4);
    }
    else
    {
        alert('Phone must contain 10 numbers.');
    }
}

Format xxx-xxx-xxxx

var oField = event.srcElement;
if (typeof(oField) != "undefined" && oField != null && oField.DataValue != null)
{
    var sTmp = oField.DataValue.replace(/[^0-9]/g, "");
    if(sTmp.length == 10)
    {
        oField.DataValue = sTmp.substr(0, 3) + "-" + sTmp.substr(3, 3) + "-" + sTmp.substr(6, 4);
    }
    else
    {
        alert('Phone must contain 10 numbers.');
    }
}

Format xxx.xxx.xxxx

var oField = event.srcElement;
if (typeof(oField) != "undefined" && oField != null && oField.DataValue != null)
{
    var sTmp = oField.DataValue.replace(/[^0-9]/g, "");
    if (sTmp.length == 10)
    {
        oField.DataValue = sTmp.substr(0, 3) + "." + sTmp.substr(3, 3) + "." + sTmp.substr(6, 4);
    }
    else
    {
        alert('Phone must contain 10 numbers.');
    }
}

Other Formatting Issues:
Remove leading digit if number is 1

    var sTmp = oField.DataValue.replace(/[^0-9]/g, "");
    if (sTmp.substr(0, 1) == "1")
    {
        sTmp = sTmp.substr(1, sTmp.length-1);
    }

Allowing only 7 digits (no area code)

    else if (sTmp.length == 7)
    {
        oField.DataValue = sTmp.substr(0, 3) + "-" + sTmp.substr(3, 4);
    }
    else
    {
        alert('Phone must contain 7 or 10 numbers.');
    }

Allowing extensions (requires area code)

    else if (sTmp.length > 10)
    {
        oField.DataValue = "(" + sTmp.substr(0, 3) + ") " + sTmp.substr(3, 3) + "-" + sTmp.substr(6, 4) + " ext: " + sTmp.substr(10, sTmp.length-10);
    }
    else
    {
        alert('Invalid phone number. If using an extension, you must enter area code also.');
    }