function TextboxIsNumeric(theTextbox, ExtraChars)
{
   var ValidChars = "0123456789" + ExtraChars;
   var Char;
   var sText =  theTextbox.value;
   var TextVal = "";  

   for (i = 0; i < sText.length; i++) 
      { 
      Char = sText.charAt(i); 
      if (!(ValidChars.indexOf(Char) == -1))
         {
            TextVal = TextVal + Char;
         }       
      }
   theTextbox.value = TextVal;
}

function replace(originalString,searchText,replaceText)
{ 
	var strLength = originalString.length; 
	var txtLength = searchText.length; 
	
	
	if ((strLength == 0) || (txtLength == 0)) 
	{ 
		return originalString;
	} 
	var i = originalString.indexOf(searchText); 
	if ((!i) && (searchText != originalString.substring(0,txtLength))) 
	{
		return originalString;
	} 
	if (i == -1) 
	{
		return originalString;
	} 
	var newstr = originalString.substring(0,i) + replaceText; 
	if (i+txtLength < strLength) 
	{
		newstr += replace(originalString.substring(i+txtLength,strLength),searchText,replaceText);
	} 
	return newstr;
} 

//Allow only valid Chars to be entered into a textbox
function TextboxValidChars(theTextbox, ValidChars)
{
    //alert("Hit TextboxValidChars: " + ValidChars);
   var Char;
   var sText =  theTextbox.value;
   var TextVal = "";  
   
   for (i = 0; i < sText.length; i++) 
      { 
      Char = sText.charAt(i); 
      if (!(ValidChars.indexOf(Char) == -1))
         {
            TextVal = TextVal + Char;
         }       
      }
   theTextbox.value = TextVal;
}


//  End -->