When we refresh the page the quotes should be refeshed(Changed)

You can generate a Random number each time the web page is called, and use that number to extract the Qoute from the source (i.e. Database, Text File, or some other website).

You can assign an ID to each of the Qoute, and then generate a Random number, that would start from 0 and would span upto the maximum number of the QuoteID you're having.

// Add one because it generates randoms equal to number passed - 1
Random random = new Random(maxQouteId + 1);

// use this random number to extract the random Qoute

Read more on Randoms here on MSDN[^].