var zipareas = [ [1, 9, 34, "South Florida"],
			[10, 59, 18, "New England"],
			[60, 69, 9, "Connecticut"],
			[70, 89, 19, "New Jersey"],
			[100, 114, 22, "New York"],
			[115, 119, 14, "Long Island"],
			[120, 129, 22, "New York"],
			[130, 149, 40, "Western New York"],
			[150, 168, 30, "Pittsburgh"],
			[169, 199, 28, "Philadelphia"],
			[200, 209, 39, "Washington DC"],
			[210, 219, 4, "Baltimore"],
			[220, 223, 39, "Washington DC"],
			[224, 224, 6, "Central Virginia"],
			[225, 228, 39, "Washington DC"],
			[229, 253, 6, "Central Virginia"],
			[254, 254, 39, "Washington DC"],
			[255, 259, 6, "Central Virginia"],
			[260, 261, 30, "Pittsburgh"],
			[262, 262, 6, "Central Virginia"],
			[263, 265, 30, "Pittsburgh"],
			[266, 267, 6, "Central Virginia"],
			[268, 276, 39, "Washington DC"],
			[277, 289, 23, "North Carolina"],
			[290, 299, 33, "South Carolina"],
			[300, 319, 2, "Atlanta/Southeast"],
			[320, 328, 5, "Central Florida"],
			[329, 334, 34, "South Florida"],
			[335, 338, 5, "Central Florida"],
			[339, 349, 34, "South Florida"],
			[350, 365, 2, "Atlanta/Southeast"],
			[366, 366, 21, "New Orleans/Gulf South"],
			[367, 369, 2, "Atlanta/Southeast"],
			[370, 385, 36, "Tennessee"],
			[386, 399, 21, "New Orleans/Gulf South"],
			[400, 433, 25, "Ohio Valley"],
			[434, 436, 26, "Ohio/North Coast"],
			[437, 438, 25, "Ohio Valley"],
			[439, 449, 26, "Ohio/North Coast"],
			[450, 462, 25, "Ohio Valley"],
			[463, 469, 7, "Chicago/Midwest"],
			[470, 478, 25, "Ohio Valley"],
			[479, 479, 7, "Chicago/Midwest"],
			[480, 499, 16, "Michigan"],
			[500, 549, 7, "Chicago/Midwest"],
			[550, 589, 17, "Minneapolis/St. Paul"],
			[590, 599, 32, "Seattle/Northwest"],
			[600, 617, 7, "Chicago/Midwest"],
			[618, 639, 35, "St. Louis"],
			[640, 651, 13, "Kansas City/Mid-America"],
			[652, 652, 35, "St. Louis"],
			[653, 653, 13, "Kansas City/Mid-America"],
			[654, 658, 35, "St. Louis"],
			[659, 699, 13, "Kansas City/Mid-America"],
			[700, 729, 21, "New Orleans/Gulf South"],
			[730, 757, 10, "Dallas"],
			[758, 759, 12, "Houston"],
			[760, 767, 10, "Dallas"],
			[768, 769, 3, "Austin/San Antonio"],
			[770, 779, 12, "Houston"],
			[780, 788, 3, "Austin/San Antonio"],
			[789, 789, 12, "Houston"],
			[790, 796, 10, "Dallas"],
			[797, 799, 3, "Austin/San Antonio"],
			[800, 819, 8, "Colorado"],
			[820, 849, 38, "Utah/Mountain West"],
			[850, 853, 29, "Arizona Phoenix"],
			[854, 859, 37, "Arizona Tucson"],
			[860, 864, 29, "Arizona Phoenix"],
			[865, 869, 37, "Arizona Tucson"],
			[870, 884, 20, "New Mexico"],
			[885, 893, 15, "Los Angeles"],
			[894, 895, 24, "Northern California"],
			[896, 919, 15, "Los Angeles"],
			[920, 922, 31, "San Diego"],
			[923, 937, 15, "Los Angeles"],
			[938, 938, 31, "San Diego"],
			[939, 961, 24, "Northern California"],
			[962, 969, 15, "Los Angeles"],
			[970, 979, 27, "Oregon"],
			[980, 994, 32, "Seattle/Northwest"],
			[995, 999, 1, "Alaska"] ] ;

function findChapter() {
	var zip = document.getElementById('zip').value;
	//javascript will treat zipcodes with a leading zero
	// as octal numbers. Force a base-10 conversion.
	var scf = parseInt(zip.substring(0,3), 10);
	var chapterID = 0;
	var chaptername = "not available";
	var url = '';
	
	for (var j=0; j < zipareas.length; j++) {
		if (scf >= zipareas[j][0] && scf <= zipareas[j][1]) {
			chapterID = zipareas[j][2];
			chaptername = zipareas[j][3];
			break;
		}
	}
	if (chapterID == 0) {
		url = 'undetermined';
	} else {
		url = '<a href="/chapter-profile.html?id='+ chapterID +'">'+ chaptername +'</a>';
	}
	document.getElementById('chapterlink').innerHTML = url;
}