1136: Incorrect number of arguments. Expected 1

what i am trying to do is by pressing zero_btn which is an object in the library to print a number in the dynamic text box ( result_txt ) which is also an existing object in the library and on stage.

my knowledge in actionscript is not much and messing with .as files is totally new to me!

so by giving you to understand what am trying to do would be much easier for you to help me as well. then thing is that this code when i locate into to .fla file works fine.

.as file

package
{
    import flash.events.MouseEvent;    
    import flash.display.Sprite;    
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;
    import flash.text.TextFormat; 
    import flash.display.SimpleButton
    
    public class displayNumbers extends Sprite
    {
        
        public function displayNumbers ()
        {
            zero_btn.addEventListener(MouseEvent.CLICK, callZero);
        }      
        
        public function callZero(e:MouseEvent):void
        
        {  
            result_txt.text = ""; 
            result_txt.length = display_txt.maxChars - display_txt.length;
            if (result_txt.length > 1)
            {
                display_txt.appendText("0");
                showSign_txt.appendText("0");         
            }
            else
            {  
                result_txt.visible = true;
                result_txt.text = "MAX INPUTS";
            }
        }//function callZero
    }//class displayNumbers
}//package

the action:

import displayNumbers;

The problem is arising from this line: noOne.callZero();

Your callZero function is expecting an event argument.  The way around this is to define the callZero finction using...

    public function callZero(e:MouseEvent=null):void