Here Mudassar Ahmed Khan has explained with an example, how to perform AlphaNumeric validation i.e. allow only Alphabets and Numbers using OnKeyPress event in jQuery.

When User types in the TextBox, the text in the TextBox will be validated using OnKeyPress event handler in jQuery and if the inputted character is not AlphaNumeric i.e. Alphabet or Number, the error message will be displayed next to the TextBox.

Here Mudassar Ahmed Khan has explained with an example, how to perform AlphaNumeric validation i.e. allow only Alphabets and Numbers using OnKeyPress event in JavaScript.

When User types in the TextBox, the text in the TextBox will be validated using OnKeyPress event handler in JavaScript and if the inputted character is not AlphaNumeric i.e. Alphabet or Number, the error message will be displayed next to the TextBox.

Here Mudassar Ahmed Khan has explained with an example, how to allow only AlphaNumeric, Dot (Period) and Underscore characters in Username using JavaScript.

When the Submit Button is clicked, the Username in the TextBox will be validated using JavaScript and Regular Expression (Regex) and if the Username is invalid, the error message will be displayed next to the TextBox using JavaScript.

Here Mudassar Ahmed Khan has explained with an example, how to perform Email validation using OnKeyPress event in JavaScript.

The OnKeyPress event does not update the value of the TextBox when accessed using JavaScript and hence OnKeyUp event handler will be used to validate Email Address dynamically when User types in the Email Address in the TextBox.