function vldLocation_ClientValidate (source, arguments)
{
    gridref = document.getElementById(clientIds.txtObsGridRef).value;
    sitename = document.getElementById(clientIds.txtObsSiteName).value;
    postcode = document.getElementById(clientIds.txtObsPostcode).value;
    
    if (gridref == "" & sitename == "" & postcode == "")
    {
        arguments.IsValid = false;
    }
    else
    {
        arguments.IsValid = true;
    }
}

function vldOtherHabitat_ClientValidate (source, arguments)
{
        ddl = document.getElementById(clientIds.ddlHabitat);
        txt = document.getElementById(clientIds.txtHabitat);
        if (ddl.value == "Other" && txt.value == "") 
            arguments.IsValid = false;
        else
            arguments.IsValid = true;
}