var xnm=4
var ynm=1
xnme = new Array(xnm)
ynme = new Array(ynm)
xtxt = new Array(xnm)
ytxt = new Array(ynm)
xunt = new Array(xnm)
yunt = new Array(ynm)
xvrb = new Array(xnm)
yvrb = new Array(ynm)


frm="cdn"
scrp="coincidence"
ttle="Coincidence Frequency"
xnme[1]="cs"
xtxt[1]="Speed of sound, c"
xunt[1]="ms<sup>-1</sup>"
xnme[2]="dp"
xtxt[2]="Thickness of panel, d"
xunt[2]="m"
xnme[3]="rho"
xtxt[3]="Density of panel, <font face=symbol>r</font>"
xunt[3]="kgm<sup>-3</sup>"
xnme[4]="ym"
xtxt[4]="Young&prime;s modulus, Y"
xunt[4]="Nm<sup>-2</sup>"


ynme[1]="fc"
ytxt[1]="Coincidence frequency, f<sub>c</sub>"
yunt[1]="Hz"

function coincidence()
{
	xvrb[1]=parseFloat(document.cdn.cs.value)
	xvrb[2]=parseFloat(document.cdn.dp.value)
	xvrb[3]=parseFloat(document.cdn.rho.value)
	xvrb[4]=parseFloat(document.cdn.ym.value)


	yvrb[1]=Math.sqrt(3)*Math.sqrt(xvrb[3]/xvrb[4])*xvrb[1]*xvrb[1]/(4*Math.atan(1)*xvrb[2])

	document.cdn.fc.value=yvrb[1]

}