You just have to join the cause on Facebook to donate a dollar to UNHCR. The technology company Microsoft has pledged to match dollar for dollar, up to $50,000, every donation to the United Nations refugee agency made on social networking site Face book.

The campaign, launched to help mark World Refugee Day on 20 June, has already received pledges of more than $10,000, to be matched by Microsoft, according to the UN High Commissioner for Refugees (UNHCR).

Donations can be made through Facebook’s Causes section, directly to the agency’s “Gimme Shelter” programme. The Face book campaign “will help users double their donation, or effectively make a donation simply by joining the Gimme Shelter cause.”

The Gimme Shelter campaign is also supported by short films directed by American actor Ben Affleck set to the Rolling Stones’ track “Gimme Shelter” – donated by Mick Jagger.

The theme for this year’s World Refugee Day is “Real People, Real Needs.” Worldwide events to mark the day include light shows, film screenings, photography exhibitions, lectures, panel discussions, food bazaars, fashion shows, cultural performances, concerts and sports contests.