function DoDealerSearch()
{
    var regEx = /\b[A-Z][A-Z0-9][A-Z0-9]?[A-Z0-9]? ?[0-9][A-Z]{2}\b/g;
        
    if(!regEx.test(document.getElementById("ctl00_ContentPlaceHolder_MainContent_txtPostcode").value.toUpperCase()))
    {
        alert('Please enter a valid postcode.');
        return false;
    }    
}