/*
===============================================================================
-- Author : Paul Backhouse
-- Description : "Common methoids" 
-- Dated created : 15/12/2009
-- Version : 1.1
===============================================================================
*/

    function imageSwap(imgSRC, objID)
    {
        document.getElementById(objID).src = imgSRC;
    }

    //show/hide content using classname
    function ShowHide(objID)
    {
        var obj = document.getElementById(objID);
        
        if (obj.className == 'Hide')
        {
            //change class to show
            obj.className = 'Show';
        } else {
            // assume is hide
            obj.className = 'Hide';
        }

    }

    // replicate "IsNumeric" VB function
    function IsNumeric(sText)
    {
       var ValidChars = "0123456789.";
       var IsNumber=true;
       var Char;

     
       for (i = 0; i < sText.length && IsNumber == true; i++) 
          { 
          Char = sText.charAt(i); 
          if (ValidChars.indexOf(Char) == -1) 
             {
             IsNumber = false;
             }
          }
       return IsNumber;
       
    }
       
    // clear a value of a form element   
    function ClearValue(objID, objValue)
    {
        //alert(objID); // debug
        if (document.getElementById(objID).value == objValue)
        {
            document.getElementById(objID).value = '';
        }
    }  

    // replicate "Left" VB function
    function Left(str, n){
	    if (n <= 0)
	        return "";
	    else if (n > String(str).length)
	        return str;
	    else
	        return String(str).substring(0,n);
    }

    // replicate "Right" VB function
    function Right(str, n){
        if (n <= 0)
           return "";
        else if (n > String(str).length)
           return str;
        else {
           var iLen = String(str).length;
           return String(str).substring(iLen, iLen - n);
        }
    }