// Roi calculator

//Main Function
function calculateSavings(){
	//initialize variables and set values 
	var avgSpam = document.mxtreme_ROI.averageSPAM2.value;
	var users = document.mxtreme_ROI.totalUsers.value;
	var avgSalary = document.mxtreme_ROI.averageSalary.value;
	var avgTime = document.mxtreme_ROI.averageTimeSpent.value;
	var mxModel = document.mxtreme_ROI.model.options[document.mxtreme_ROI.model.selectedIndex].value;
	
	// Perform calculations
	var spamCostPerMonth = (avgSpam * (avgTime/60/60) * 30 * avgSalary * users);
	var threeYearSpam = (spamCostPerMonth * 36);
	var threeYearMxtreme = (unitCost(mxModel)* numberOfUnits(users));
 	
	// write out the final calculations
	document.mxtreme_ROI.monthCost.value = moneyRound(spamCostPerMonth);
	document.mxtreme_ROI.threeYearSpam.value = moneyRound(threeYearSpam);
	document.mxtreme_ROI.threeYearMXtreme.value = moneyRound(threeYearMxtreme);
	document.mxtreme_ROI.totalSavings.value = moneyRound(threeYearSpam-threeYearMxtreme);
}

// Rounds Numbers to a Currency Standard, adds commas
function moneyRound(cost){
   	result="$"+Math.floor(cost)
   	x = result.length
   	if (cost>1000 && cost<999999) {  
     		result="$"+result.substring(1,x-3)+","+result.substring(x-3,x)
    	} else if (cost>1000000) {  
     		result = "$"+result.substring(1,x-6)+","+result.substring(x-6,x-3)+","+result.substring(x-3,x)
    	}
   	return(result)
}

//Calculates the unit cost dependening on the unit selected
function unitCost(mxModel){
	if (mxModel=='200'){
		return 9000;
	} else if (mxModel=='1000'){
		return 27000;
	} else if (mxModel=='5000'){
		return 63000;
	} 
}

//Calculates how many units are needed
function numberOfUnits(users){
	var maxUsers = document.mxtreme_ROI.model.options[document.mxtreme_ROI.model.selectedIndex].value;
	if (users<=maxUsers){
		return 1;
	} else if (users>maxUsers){
		return (Math.ceil(users/maxUsers));
	}
} 
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////