How to identify unused labels in application

We often creates labels in our development environment and we not use the labels.Following is a job to identify unused labels in application .

Here my label file is IFC

static void I4C_UnusedLabels(Args _args)
{
str 50 labelId;
int i;
int maxLabel = 2000;
xRefNames names;
XRefReferences ref;

str info = "LabelId#LabelStr\n"
;

while (i <= maxLabel) {
labelId = "@IFC" + int2str(i);
// The particular label file.
select recid from names
where names.Name == labelid
exists join ref
where names.RecId == ref.xRefNameRecId;

if (! names.RecId)
{
info += strfmt("%1#%2\n", labelId,

SysLabel::labelId2String(labelId));
}

i++;
}

}