I have three checkboxes and a textbox now If I write something in textbox and check the bold checkbox the text should appear with bold effect and similarly italic and underline
You can do that using simple CSS and a little jQuery code.
1.First define your cascading style sheet classes
2.Load jQuery
3.Write the function for switching the classes
5.Modified html
Bold: Italic: Underline:
jsfiddle link: http://jsfiddle.net/deepumohanp/t2wKP/