Fetching a script name for AddComponent from a text - class doesn't exist?

I'm planning to write a short format for the levels in my game - as part of this, I'm including a tag that should let me include a script for the given level:

     /* given a text asset, this function finds lines beginning with EVENT;
 and attaches the component with the name given after the semicolon */
 
 function LoadSituation (target : TextAsset) {
     var rawLines : String[] = target.text.Split("\n"[0]);
     for(var line : String in rawLines){
         if (line.StartsWith("EVENT")){
             this.gameObject.AddComponent(line.Split(";"[0])[1].ToString());
         }        
     }
 }

However, when I test this function with the test line:

 EVENT;DemoMatch

I get this error:

 Can't add component because class 'DemoMatch' doesn't exist!
 UnityEngine.GameObject:AddComponent(String)
 SituationLoader:LoadSituation(TextAsset) (at Assets/Scripts/SituationLoader.js:35)
 SituationLoader:Start() (at Assets/Scripts/SituationLoader.js:10)

Adding "DemoMatch" as a component the ordinary way (AddComponent("DemoMatch") ) works - however, using the same string from the text file doesn't, even when the strings are seemingly equivalent.

Is there any reason I can't add components like this, or am I simply making a mistake somewhere?