void update_ext_reloc(ALL_TABLES* tfinal, ALL_TABLES* t, int ex_tabix, 
   int new_ref, int new_tabix, int modify_code , int t_code_offset, 
   int new_dseg_adr)
   /* Called when new information shows up about an external dseg rence.
    * Search the relocation table t->reloc[] for an extdsegref ref field
    * having a tabix field == ex_tabix
    * When found at t->reloc[i], 
    *   update the ref field of t->reloc[i] to new_ref
    *   update the tabix field of t->reloc[i] to new_tabix
    *   If (modify_code),
    *      modify tfinal->code[adr+t_code_offset].u.y to new_dseg_adr
    *      If new_tabix == NO_MOD, then the adr field of the relocation
    *      item must be modified now (append_reloc will zero the tabix
    *      field when it sees such an item and leave the adr field 
    *      unmolested)
    */
{
 	int i;
 	reloc_fields r;
 	
 	for(i = 0; i <= t->last_reloc; i++)
 	{
	 	  r = t->reloc[i];
		  if(r.r.tabix == ex_tabix && r.r.ref == EXTDSEGREF)
		  {
    	   			 r.r.ref = new_ref;
    	  			 r.r.tabix = new_tabix;
    	  			 if(modify_code)
	 			   	  				tfinal->code[r.r.adr + t_code_offset].u.y = new_dseg_adr;
				     if(new_tabix == NO_MOD)
								    r.r.adr += t_code_offset;
    	  			 t->reloc[i] = r;
		  }
    }
}  /* update_ext_reloc */