[Javascript] Is Numeric Function

[Grinwald, Uri]

Hi List Members.

I have a function that checks for numbers:
It won't allow for space, so I need to either reflect that an empty
character is allowed within the function.

On a separate use of this function how can I replace any empty spaces
with a "-" 
Here is my function at the top of page.
I call all my validations further down with a validate(obj) function.


function IsNumeric(passedVal)

{

var ValidChars = "0123456789.()-";
var IsNumber=true;
var Char;
if(passedVal == "")
	{return false;}
	for (i = 0; i < passedVal.length && IsNumber == true; i++)
	{
		Char = passedVal.charAt(i);
		if (ValidChars.indexOf(Char) == -1)
		{
		IsNumber = false;
		}
		}
	return IsNumber;

	}

////and later I do the following...
if(!IsNumeric(obj.dynTelEng_11.value))
	{
	msgError = msgError + '\n' + 'Telephone Number must be numeric';
	}

Etc...

Any help would be  greatly appreciated.
Uri