HI There 

Im wondering if someone can help me , ive created a forula but i cant get it to work , wondering if somone can take a look.

IF(ISBLANK( MailingCountry ), "Unknown", 
IF(CONTAINS("Belarus:Bulgaria:Czech Republic:Germany:Hungary:Moldova:Poland:Romania:Russia:Slovakia:Ukraine:Armenia:Azerbaijan:Georgia:Kazakhstan:Estonia:Latvia:Lithuania,") "Eastern Europe", 
IF(CONTAINS(" Andorra:Austria:Belgium:France:Germany:Greece:Ireland:Italy:Liechtenstein:Luxembourg:Malta:Monaco:Netherlands:Norway:Portugal:San Marino:Spain:Sweden:Switzerland:Turkey",) "Western Europe",
IF(CONTAINS("Denmark:Norway:Sweden:Finland:Iceland:Aland Islands;Faroe Islands:Greenland:Svalbard",) "Scandinavia",
IF(CONTAINS("Bahrain:Iraq:Iran:Israel:Jordan:Kuwait:Lebanon:Oman:Palestine:Qatar:Saudi Arabia:Syria:United Arab Emirates:Yemen:UAE",) "Middle East",
IF(CONTAINS("Australia:Fiji:French Polynesia:Guam:Kiribati:Marshall Islands:Micronesia:New Caledonia:New Zealand:Papua New Guinea:Samoa:Solomon:Tonga:Vanuatu",) "Oceania",
IF(CONTAINS("Afganistan:Armenia:Azerbaijan:Bangladesh:Bhutan:Brunei Darussalam:Cambodia:China:Georgia:Hong Kong:India:Indonesia:Japan:Kazakhstan:North Korea:South Korea:Kyrgyzstan:Laos:Macao:Malaysia:Maldives:Mongolia:Myanmar:Nepal:Pakistan:Phillipines:Singapore:Sri Lanka:Taiwan:Tajikistan:Thailand:Timor Leste:Turkmenistan:Uzbekistan:Vietnam:Burma",) "Asia",
IF(CONTAINS("Bermuda:Canada:Greenland:Saint Pierre and Miquelon:United States:USA",) "North America",
IF(CONTAINS("Argentina:Bolivia:Brazil:Chile:Colombia:Ecuador:Falkland Islands:French Guiana:Guyana:Paraguay:Peru:Suriname:Uruguay:Venezuela",) "South America",
IF(CONTAINS("Belize:Costa Rica:El Salvador:Guatemala:Honduras:Mexico:Nicaragua:Panama",) "Central America",
IF(CONTAINS("Anguilla:Antigua and Barbuda:Aruba:Bahamas:Barbados:Bonaire:British Virgin Islands:Cayman Islands:Cuba:Curaçao:Dominica:Dominican Republic:Grenada:Guadeloupe:Haiti:Jamaica:Martinique:Monserrat:Puerto Rico:Saint-Barthélemy:St. Kitts and Nevis:Saint Lucia:Saint Martin:Saint Vincent:Grenadines:Sint Maarten:Trinidad and Tobago:Turks and Caicos Islands:Virgin Islands",) "Carribean",
IF(CONTAINS("Burundi:Comoros:Djibouti:Eritrea:Ethiopia:Kenya:Madagascar:Malawi:Mauritius:Mayotte:Mozambique:Reunion:Rwanda:Seychelles:Somalia
Tanzania:United Republic of Uganda:Zambia:Zimbabwe:Angola:Cameroon:Central African Republic:Chad:Congo:Equatorial Guinea:Gabon:Sao Tome and Principe:Algeria:Egypt:Libyan Arab:Jamahiriya:Morroco:South Sudan:Sudan:Tunisia:Western Sahara",) "Africa",)))))))))))