GetComponent Error

Please post your code so we can track down the exact problem. Telling from the error, you are trying to access a method / function using 'GetComponent' when GetComponent is used for Unity types only. Here is the component list from Unity documentation:

http://unity3d.com/support/documentation/ScriptReference/Component.html

You can use GetComponent to cache a copy of the script you are trying to access:

var other : ScriptName = gameObject.GetComponent(ScriptName);

then access the function by doing other.DoWorkFromScript();