function calc()
{

	var backstake = parseFloat(document.calcform.backstake.value)
	var backodds = parseFloat(document.calcform.backodds.value)
	var backcommission = parseFloat(document.calcform.backcommission.value)
	var layodds = parseFloat(document.calcform.layodds.value)
	var laycommission = parseFloat(document.calcform.laycommission.value)
	
	var laycommpercent = laycommission/100
	var backcommpercent = backcommission/100
	
	var radiochoice;
	
	for(i=0;i<document.calcform.typeofbet.length;i++)
	{
		if(document.calcform.typeofbet[i].checked)
			radiochoice = document.calcform.typeofbet[i].value;
	}
    
    if (radiochoice=="qualifier")
	{
	var backgainbackwin = backstake * (backodds-1) * (1-backcommpercent)
	var backgainbacklose = backstake * -1
	
	var laystake = (backgainbackwin + backstake) / (layodds - laycommpercent)
	
	var laygainbackwin = -1 * laystake * (layodds-1)
	var laygainbacklose = laystake * (1-laycommpercent)
	
	var gaindifference = backgainbackwin + laygainbackwin
	var retentionpercent = ((gaindifference+backstake)/backstake) * 100
    }

	if (radiochoice=="freesr")
	{	
	var backgainbackwin = backstake * (backodds) * (1-backcommpercent)
	var backgainbacklose = 0
	
	var laystake = (backgainbackwin / (layodds - laycommpercent))
	var laygainbackwin = (-1 * laystake * (layodds-1))
	var laygainbacklose = (laystake * (1-laycommpercent))
	
	var gaindifference = backgainbackwin + laygainbackwin
	var retentionpercent = (gaindifference/backstake) * 100
	}	

	if (radiochoice=="freesnr")
	{	
	var backgainbackwin = backstake * (backodds-1) * (1-backcommpercent)
	var backgainbacklose = 0
	
	var laystake = (backgainbackwin / (layodds - laycommpercent))
	var laygainbackwin = (-1 * laystake * (layodds-1))
	var laygainbacklose = (laystake * (1-laycommpercent))
	
	var gaindifference = backgainbackwin + laygainbackwin
	var retentionpercent = ((gaindifference/backstake) * 100)
	}
	
	var liability = laystake * (layodds-1)
	
	var netresultbackbackwin = backstake * backodds
	var netresultlaybackwin = -1 * laystake * layodds
	var netresultbacklaywin = 0
	var netresultlaylaywin = laystake * (1-laycommpercent)
	
	liability = liability.toFixed(2)
	netresultbackbackwin = netresultbackbackwin.toFixed(2)
	netresultlaybackwin = netresultlaybackwin.toFixed(2)
	netresultbacklaywin = netresultbacklaywin.toFixed(2)
	netresultlaylaywin = netresultlaylaywin.toFixed(2)
	laystake = laystake.toFixed(2)
	backgainbackwin = backgainbackwin.toFixed(2)
	backgainbacklose= backgainbacklose.toFixed(2)
	laygainbackwin = laygainbackwin.toFixed(2)
	laygainbacklose = laygainbacklose.toFixed(2)
	gaindifference = gaindifference.toFixed(2)
	retentionpercent = retentionpercent.toFixed(2)
	
	document.calcform.liability.value = liability
	document.calcform.netresultbackbackwin.value = netresultbackbackwin
	document.calcform.netresultlaybackwin.value = netresultlaybackwin
	document.calcform.netresultbacklaywin.value = netresultbacklaywin
	document.calcform.netresultlaylaywin.value = netresultlaylaywin
	document.calcform.laystake.value = laystake
	document.calcform.backgainbackwin.value = backgainbackwin
	document.calcform.backgainbacklose.value = backgainbacklose
	document.calcform.laygainbackwin.value = laygainbackwin
	document.calcform.laygainbacklose.value = laygainbacklose
	document.calcform.gaindifference.value = gaindifference
	document.calcform.retentionpercent.value = retentionpercent

}