JSFiddle - React, Tailwind, and code Playground

JavaScript

function getParamValue( name )
{
  name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
  var regexS = "[\\?&]"+name+"=([^&#]*)";
  var regex = new RegExp( regexS );
  var results = regex.exec( "http://localhost/resume/Template/index.html?msg=Message%20Sent%20Successfully" );
  if( results == null )
	return "";
  else
	return decodeURI(results[1]);
}

alert(getParamValue('msg'));