Is numeric

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;

}