;Lisp: XLTH.LSP
					;
;;;Elise Moss
;;;www.mossdesigns.com
;;;December 2004
					;
					;Function:		User selects an xref and then freeze all layers in that xref that have a user set pattern in the name.
					;
					;	THE AUTHOR PROVIDES THIS PROGRAM "AS IS" AND WITH ALL FAULTS.  THE
					;	AUTHOR SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTY OF MERCHANTABILITY
					;	OF FITNESS FOR A PARTICULAR USE.  THE AUTHOR DOES NOT WARRANT THAT
					;	THE OPERATION OF THE PROGRAM WILL BE UNINTERRUPTED OR ERROR FREE.
;;; ---------------------------------------------------------------------------------
(defun c:xlth ()
					; first user must select an xref
  (prompt "\nSelect the xref to freeze layers: ")
  (setq xname (entsel))
  (setq xname (car xname))
					;get data of selected object
  (setq xdata (entget xname))
  (setq xdata-type (cdr (assoc 0 xdata)))
  (while (/= xdata-type "INSERT")	; then selected item was not an xref- user must reselect
    (progn
      (alert
	"Selected object was not an XREF - Please pick again."
      )
      (setq xname (entsel))
      (setq xname (car xname))
					;get data of selected object
      (setq xdata (entget xname))
      (setq xdata-type (cdr (assoc 0 xdata)))
    )					;end progn
  )					; end while
					; now we have an xref...let's look at the xref's name
  (setq xref-name (cdr (assoc 2 xdata)))
					; now we can look at all the layers associated with that xref
  (setq pattern (strcat xref-name "*"))
  (setq LST (tblnext "LAYER" T))
  (setq lst-name (cdr (assoc 2 lst)))

  (while (/= lst nil)

    (if	(wcmatch lst-name pattern)
      (setq xref-laylist (append xref-laylist (list lst-name)))
    )					; end if
    (setq LST (tblnext "LAYER"))
    (setq lst-name (cdr (assoc 2 lst)))
  )					; end while
  ;; we have now created a list of all the layers associated with that xref
;;;we want to freeze any layers that have patt2 in them
					; get the number of layers in the list	
  (setq laynum (length xref-laylist))
  (setq index 0)			; create a counter
  ;;prompt for pattern
  (setq
    patt2 (getstring "\nEnter layer name filter to use for freeze: ")
  )
  (setq patt2 (strcat "*" patt2 "*"))
  (while (< index laynum)
					; get a layer in the list
    (setq layname (nth index xref-laylist))

					; check to see if this layer has the pattern in it
    (setq flag (wcmatch layname patt2))
					; if flag is T, then freeze the layer
    (if	(= flag T)
      (command "-layer" "f" layname "")
    )					;end if
					; go on to the next layer name
    (setq index (1+ index))
  )					;end while  

)
(princ "\nType 'xlth' to freeze layers in an xref.")