VBScript is not case sensitive. JScript on the other hand, is case sensitive. So when Web scripts reference JScript keywords, care must be taken to type the keyword exactly as spelled in the reference documentation. The same applies to JScript variables and object, method, and property names. They should be used exactly as declared.

For example, code for Date object below will generate a “‘date’ is undefined” script error in IE:
var currentDate = new date();

However, this code below works properly:
var currentDate = new Date();