diff --git a/texttools.tcl b/texttools.tcl
index 9eb219e..d8a1096 100755
--- a/texttools.tcl
+++ b/texttools.tcl
@@ -1,5 +1,25 @@
 #!/usr/bin/env wish
 
+set active_transform 0
+
+proc oneline {text} {
+  return [regsub -all \n+ $text " "]
+}
+
+proc wordcount {text} {
+  set lines [expr [llength [split $text \n]] - 1]
+  set words [llength [regexp -all -inline {\S+} $text]]
+  set len [string length $text]
+
+  lappend out $lines
+  lappend out $words
+  lappend out $len
+  return $out
+}
+
+lappend transforms [list {One line} oneline]
+lappend transforms [list {Line/Word/Char} wordcount]
+
 wm geometry . 750x650
 wm title . "Text Tools"
 
@@ -7,8 +27,10 @@ text .content
 text .output
 listbox .transform
 
-.transform insert end {One line}
-.transform insert end Line/Word/Char
+foreach {elem} $transforms {
+  .transform insert end [lindex $elem 0]
+}
+.transform selection set $active_transform
 
 grid .transform -row 1 -column 1 -rowspan 2
 grid .content -row 1 -column 2
@@ -16,23 +38,23 @@ grid .output -row 2 -column 2
 
 focus .content
 
-proc wordcount {} {
+proc update_output {} {
+  global active_transform
+  global transforms
+
   set text [.content get 1.0 end]
 
-  set lines [expr [llength [split $text \n]] - 1]
-  set words [llength [regexp -all -inline {\S+} $text]]
-  set len [string length $text]
-
-  lappend out $lines
-  lappend out $words
-  lappend out $len
+  set tf [lindex $transforms $active_transform]
+  set out [[lindex $tf 1] $text]
   .output replace 1.0 end $out
 }
 
-bind .content <KeyRelease> wordcount
+bind .content <KeyRelease> update_output
 
-proc select_transform {} {
-  puts {transform selected}
+proc select_transform {args} {
+  global active_transform
+  set active_transform [.transform curselection]
+  update_output
 }
 
 bind .transform <Button-1> select_transform