Ok, I am sorry, I think there were still two bad lines of code in that example for trying to get a function into the class dynamically with a string variable.
But I am able to add properties to the class dynamically based on the value of a string variable: var sNewProperty:String; sNewProperty = "specialVar"; dClass1[sNewProperty] = "You can, you can see my dynamic variable!"; trace(dClass1[sNewProperty]); trace(dClass1.specialVar); //will print the same thing as the previous line, so the actual property name is "specialVar" from the string variable.