A simple JS function to determine if the text is numeric

/*****************************************************
* Determine if it is a number (integer, decimal, not including negative numbers)
* October 10, 2014 22:38:19
*****************************************************/
function Isnumber (str) {
var re =/^ ([0-9]+) ([.]?) ([0-9]*) $/;
return Re.test (str);
}

This function is born out of a network text, at that time is take doctrine, but the test found that 2q also returned true, so review, the original original author. Can match all characters inadvertently, correct to match the decimal point to use [.]

A simple JS function to determine if the text is numeric