//Set Up global variables of correct size

var numcalcs=1    //number of calculations on the page

var xnm=4  //maximum number of independant variables
var ynm=1  //maximum number of dependant variables

xnme=new Array(numcalcs)
ynme=new Array(numcalcs)

xtxt = new Array(numcalcs)
ytxt = new Array(numcalcs)

xunt = new Array(numcalcs)
yunt= new Array(numcalcs)

xvrb = new Array(numcalcs)
yvrb= new Array(numcalcs)

for (i=0;i<numcalcs;i++){

	xnme[i]=new Array(xnm)
	ynme[i]=new Array(ynm)
	
	xtxt[i] = new Array(xnm)
	ytxt[i] = new Array(ynm)

	xunt[i] = new Array(xnm)
	yunt[i] = new Array(ynm)

	xvrb[i] = new Array(xnm)
	yvrb[i] = new Array(ynm)
}

frm = new Array(numcalcs)
scrp = new Array(numcalcs)
ttlem = new Array(numcalcs)

//+++++++++
// Start calc 1

calcnum=0

frm[calcnum]="dg"
scrp[calcnum]="drag"
ttlem[calcnum]="Aerodynamic Drag"

xnme[calcnum][1]="cd"
xtxt[calcnum][1]="drag coefficient <font face=times size=+1><i>C</i></font><sub>d</sub>"
xunt[calcnum][1]="&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"
xnme[calcnum][2]="A"
xtxt[calcnum][2]="frontal area, <font face=times size=+1><i>A</i></font>"
xunt[calcnum][2]="m<sup>2</sup>"
xnme[calcnum][3]="rho"
xtxt[calcnum][3]="density of fluid, <font face=times size=+1><i>&rho;</i></font>"
xunt[calcnum][3]="kgm<sup>-3</sup>"
xnme[calcnum][4]="v"
xtxt[calcnum][4]="velocity, <font face=times size=+1><i>v</i></font>"
xunt[calcnum][4]="ms<sup>-1</sup>"


ynme[calcnum][1]="F"
ytxt[calcnum][1]="aerodynamic drag force, <font face=times size=+1><i>F</i></font>"
yunt[calcnum][1]="N"


function drag(cm){
xvrb[cm][1]=parseFloat(document.dg.cd.value)
xvrb[cm][2]=parseFloat(document.dg.A.value)
xvrb[cm][3]=parseFloat(document.dg.rho.value)
xvrb[cm][4]=parseFloat(document.dg.v.value)

yvrb[cm][1]=xvrb[cm][1]*xvrb[cm][2]*xvrb[cm][3]*xvrb[cm][4]*xvrb[cm][4]/2

document.dg.F.value=yvrb[cm][1]


}