Question

There r 2 buttons RED and BLUE.
If click on RED some ‘sample code’ has to come and moving to BLUE ‘sample code has to hide and ‘New paragraph’ has to come and vice versa.

Answer 1

You’d add onClick listeners. You could do these easy enough with JQuery.

Something like…

$.('#myRedbutton').click(function(){
  //Do the red button stuff.
};

$.('#myBluebutton').click(function(){
  //Do the blue button stuff.
};

For pure Javascript you could edit the HTML of the button like so..

 <button onclick="redButton()">Red</button>

Clicking the above button would invoke redButton().