The Global object provides methods, which can be accessed globally

		eval(expression)  : evaluates and returns the value of the expression. 
		parseInt(string)  : parses the string in to an integer. 
		parseFloat(string): parses the string as a floating-point number. 
		isFinite(number)  : returns true if the number is finite, otherwise false. 
		isNaN(number)     : returns true if the number is NaN (Not A Number), otherwise false.