Default Dimension in AX 2012

DimensionDisplayValue                              dimensionvalues;
DimensionAttributeLevelValueAllView     dimAttrView;
DimensionAttribute                                     dimAttr;
str                                                                 proj,bu,dept,cc;

while select DisplayValue from dimAttrView
   where dimAttrView.ValueCombinationRecId == _ledgerDimension
     join BackingEntityType from dimAttr
    where dimAttr.RecId == dimAttrView.DimensionAttribute
{

switch (dimAttr.BackingEntityType)
{
case tableNum(DimAttributeOMBusinessUnit):
bu = dimAttrView.DisplayValue;
break;

case tableNum(DimAttributeOMDepartment):
dept = dimAttrView.DisplayValue;
break;

case tableNum(DimAttributeProjTable):
proj = dimAttrView.DisplayValue;
break;
case tableNum(DimAttributeOMCostCenter):
cc = dimAttrView.DisplayValue;
break;
}

}
dimensionvalues = dept+"-"+proj+"-"+cc;