Java.lang.NoSuchMethodError: main, only when I run project, not file

Question

When I am running my project to test it I am getting the following error message.
Exception in thread "main" java.lang.NoSuchMethodError: main
I have checked all the files are in the corrcet place, and all called what the class is called, which they are, I do not know where else to look. And I have to hjand this in is a week and a half!!!
Also, the error only happens when I run the PROJECT and not when I run the file on its own. Below is the code. Does anyone have any ideas to help me?
public class ToolList
     private Tool[] toolArray;
     public ToolList()
          toolArray = new Tool[100];
          for (int i=0;i<toolArray.length;i++)
               toolArray=null;
     }//end toolList default constructor
     public boolean addTool (Tool toolIn)
          for (int i=0;i<toolArray.length;i++)
               if (toolArray[i]==null)
                    toolArray[i]=toolIn;
                    return true;
          return false;
     public static void main(String args[])
               Tool Hammer = new Tool("Hammer","H0001",16.45F);
               ToolList tl1 = new ToolList();
               if (tl1.addTool(Hammer) ) System.out.println("Tool added");
Thanks
Java Chick :)

Answer 1

Thanks all!
"Java has no concept of a 'project' so I assume that you are using an IDE for development. Most IDEs have a 'project' concept and some means of defining the 'main' class for the 'project'. Which IDE are you using?
I am using JCreator V3 LE. I have many files set up, Tool.java, ToolList.java, Company.java, Customer.java and CustomerList.java.
At the moment I am just tesing each class as I go and adding Main to the bottom of the classs I am testing.
but, as this one has an array that refers to other objects I thought I had to create this in a seperate file and run the group of files together.
"James 91 - Environment Variables"
When I check the class path I see the following:
C:\Program Files\Xinox Software\JCreatorV3 LE\MyProjects\Main Project\classes;C:\Program Files\Java\jdk1.5.0\jre\lib\rt.jar;C:\Program Files\Java\jdk1.5.0\lib\dt.jar;C:\Program Files\Java\jdk1.5.0\lib\tools.jar;C:\Program Files\Java\jdk1.5.0\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.5.0\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.5.0\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.5.0\jre\lib\ext\sunpkcs11.jar
Should I change this to C\Program Files\Java\jdk1.5.0\lib\tools.jar
Thanks
Java Chick.