no display name and no $DISPLAY environment variable
    while executing
"load /enadisk/commun/linux/local/ActiveTcl-8.6.11/lib/libtk8.6.so Tk"
    ("package ifneeded Tk 8.6.11" script)
    invoked from within
"package require Tk"
    (in namespace eval "::request" script line 3)
    invoked from within
"namespace eval ::request $script"
    ("::try" body line 12)
OUTPUT BUFFER:
 #!/usr/local/bin/wish
 
 package require Tk
 
 proc setBalloonHelp {w msg args} {
     array set opt [concat { -tag ""} $args]
     if {$msg ne ""} then {
	 set toolTipScript\
		 [list showBalloonHelp %W [string map {% %%} $msg]]
	 set enterScript [list after 1000 $toolTipScript]
	 set leaveScript [list after cancel $toolTipScript]
	 append leaveScript \n [list after 200 [list destroy .balloonHelp]]
     } else {
	 set enterScript {}
	 set leaveScript {}
     }
     if {$opt(-tag) ne ""} then {
	 switch -- [winfo class $w] {
	     Text {
		 $w tag bind $opt(-tag)  $enterScript
		 $w tag bind $opt(-tag)  $leaveScript
	     }
	     Canvas {
		 $w bind $opt(-tag)  $enterScript
		 $w bind $opt(-tag)  $leaveScript
	     }
	     default {
		 bind $w  $enterScript
		 bind $w  $leaveScript
	     }
	 }
     } else {
	 bind $w  $enterScript
	 bind $w  $leaveScript
     }
 }
 
 proc showBalloonHelp {w msg} {
     set t .balloonHelp
     catch {destroy $t}
     toplevel $t -bg black
     wm overrideredirect $t yes
     if {$::tcl_platform(platform) == "macintosh"} {
	 unsupported1 style $t floating sideTitlebar
     }
     pack [label $t.l -text [subst $msg] -bg yellow -font {Helvetica 9}]\
	     -padx 1\
	     -pady 1
     set width [expr {[winfo reqwidth $t.l] + 2}]
     set height [expr {[winfo reqheight $t.l] + 2}]
     set xMax [expr {[winfo screenwidth $w] - $width}]
     set yMax [expr {[winfo screenheight $w] - $height}]
     set x [winfo pointerx $w]
     set y [expr {[winfo pointery $w] + 20}]
     if {$x > $xMax} then {
	 set x $xMax
     }
     if {$y > $yMax} then {
	 set y $yMax
     }
     wm geometry $t +$x+$y
     set destroyScript [list destroy .balloonHelp]
     bind $t  [list after cancel $destroyScript]
     bind $t  $destroyScript
 }
 
 # demo
 if true {
     pack [button .b -text tryme -command {puts "you did it!"}] -side right
     setBalloonHelp .b "Text that describes\nwhat the button does"
     #
     pack [text .t -width 30 -height 5] -expand yes -fill both
     .t insert end abcDEFghiSLDKFJSKDLFJQMLSDKFJ
     .t tag configure yellow -background red
     .t tag add yellow 1.1 1.12
     setBalloonHelp .t "Colorised Text" -tag yellow
     #
     pack [canvas .c] -expand yes -fill both -side right
     set id [.c create rectangle 10 10 100 100 -fill white]
     setBalloonHelp .c {Geometry: [.c coords $::id]} -tag $id
 }