function analyze(form) {
		
	if (form.sex[0].checked) {
		var sex = 0
	} else {
		if (form.sex[1].checked) {
		var sex = 1
		} else {
			alert("Please check male or female.");
			return false
		}
	}

var age = form.age.value;
var pre = form.pre.value;
var g, h, PriorOR, CACLRpos, CACLRneg;

var POR = new Array();  //create Prior Odds Ratios arrays [sex][age][presentation]
for (g = 0; g < 4; g++) {POR[g] = new Array()};
for (h = 0; h < 2; h++) {POR[h][g] = new Array()};

POR[0][0] = [.02, .05, .28, 2.3]  //  male 30-39
POR[0][1] = [.06, .16, .86, 6.9]  //  male 40-49
POR[0][2] = [.11, .27, 1.43, 11.5] // male 50-59
POR[0][3] = [.14, .39, 2.0, 16.54] // male 60 & up
POR[1][0] = [.003, .008, .04, .35] // female 30-39
POR[1][1] = [.01, .03, .15, 1.23] //  female 40-49
POR[1][2] = [.03, .09, .48, 3.85]  // female 50-59
POR[1][3] = [.08, .23, 1.19, 9.64] // female 60 & up

PriorOR = POR[sex][age][pre];  // Prior Odds Ratio for sex-age-presentation
var PriorProb = Math.round((PriorOR/(PriorOR + 1)*100)); // Prior Probability

if (PriorProb == 0) {form.PriorProb.value = "< 1%"}
  else {form.PriorProb.value = PriorProb + "%"}

	if (age == 0) { 		// age less than 40
		CACLRpos = 2.58;	// Calcium present
		CACLRneg = 0.43		// Calcium absent
	} else if (age == 1){ 		// age 40 - 49
  		CACLRpos = 1.77; 
  		CACLRneg = 0.30
	} else {			// age 50 and up
		CACLRpos = 1.5;
		CACLRneg = 0.01
        }
		
form.CACpos.value = Math.round((PriorOR*CACLRpos)/((PriorOR*CACLRpos) + 1)*100) + "%";
var CACneg = Math.round((PriorOR*CACLRneg)/((PriorOR*CACLRneg) + 1)*100);
   
if (CACneg < 1) {form.CACneg.value = "< 1%"}
  else {form.CACneg.value = CACneg + "%"}

	if (sex == 0) {   // Male Sensitivity: 72% Specificity: 77%
		var TreadLRpos = 3.1304;
		var TreadLRneg = 0.3636
	} else {	 // Female Sensitivity: 61% Specificity: 70%
		var TreadLRpos = 2.0333;
		var TreadLRneg = 0.5571
	}

form.Treadpos.value = Math.round((PriorOR*TreadLRpos)/((PriorOR*TreadLRpos) + 1)*100) + "%";
var Treadneg = Math.round((PriorOR*TreadLRneg)/((PriorOR*TreadLRneg) + 1)*100);

if (Treadneg < 1) {form.Treadneg.value = "< 1%"}
  else {form.Treadneg.value = Treadneg + "%"}

return;
}