function validateSAID(elementID)
{
var SAIDRegEx = /^(((\d{2}((0[13578]|1[02])(0[1-9]|[12]\d|3[01])|(0[13456789]|1[012])(0[1-9]|[12]\d|30)|02(0[1-9]|1\d|2[0-8])))|([02468][048]|[13579][26])0229))(( |-)(\d{4})( |-)(\d{3})|(\d{7}))/;
if (SAIDRegEx.test(document.getElementById(elementID).value)) return true; return false;
}
Take a look at this blog post for more information about SA ID number structure and validation.
