func mdi_dpc(head)
 ;returns dpc as a string (usually 0x...) or an empty string if not found
 hb = bmap(head)
 nl = num_elem(hb)/80
 if nl le 0 then return, 0
 redim, hb, 80, nl
 gotem = 0		;used to count how many we got
 ;look for DPC
 for i=1,nl-1 do {
 s=upcase(smap(hb(*,i)))
 if strpos(s,'DPC') eq 0 then { s = strskp(s,'=') return, s }
 }
 return, ''
 endfunc