function checnum(as)
{
	var dd = as.value;
	
	if(isNaN(dd))
	{
		dd = dd.substring(0,(dd.length-1));
		as.value = dd;
	}		
}

function checnum2(as)
{
	var dd = as.value;
	if(isNaN(dd) || dd > 90 || dd <=0 )
	{
		dd = dd.substring(0,(dd.length-1));
		as.value = dd;
	}
}


function calsi()
{
	var ty = document.sint.ss.value;
	var ty2 = document.sint.ss2.value;
	var an = document.sint.res4.value;
	var o = document.sint.res1.value;
	var h = document.sint.res2.value;
	var a = document.sint.res3.value;
	var b = document.sint.res5.value;
	var ff = false;

	if(ty == 4 || ty2 == 4)
		an = null;
	if(ty == 1 || ty2 == 1)
		o = null;
	if(ty == 2 || ty2 == 2)
		h = null;
	if(ty == 3 || ty2 == 3)
		a = null;

	if(an == "" || o == "" || h == "" || a == "")
	{
		alert(" Please enter all required feilds ");
	}

	if(o != null && o != 0 && h != null && h != 0){
		an = Math.round(Math.asin(o/h)*180/Math.PI*100)/100;
		document.sint.res4.value=an;
	}
	else if(a != null && a != 0 && h != null && h != 0){
		an = Math.round(Math.acos(a/h)*180/Math.PI*100)/100;
		document.sint.res4.value=an;
	}
	else if(o != null && o != 0 && a != null && a != 0){
		an = Math.round(Math.atan(o/a)*180/Math.PI*100)/100;
		document.sint.res4.value=an;
	}

	if(ty == 1 || ty2 == 1)
	{
		if(h != null)
		{
			deg = Math.sin(an*Math.PI/180);
			o= Math.round(deg*h*10000)/10000;
		}
		else
		{
			deg = Math.tan(an*Math.PI/180);
			o=Math.round(deg*a*10000)/10000;
		}
		document.sint.res1.value=o;
	}
	if(ty == 2 || ty2 == 2)
	{
		deg = Math.sin(an*Math.PI/180);
		h= Math.round(o/deg*10000)/10000;
		document.sint.res2.value=h;
	}
	if(ty == 3 || ty2 == 3)
	{
		deg = Math.tan(an*Math.PI/180);
		a= Math.round(o/deg*10000)/10000;
		document.sint.res3.value=a;
	}

	var be = 90-an;
	document.sint.res5.value=be;

	return false;
}

function modf()
{
	for(var h=1; h<5; h++)
	{
		var dd = "document.sint.res"+h;
		ss = eval(dd);
		ss.disabled=false;
		ss.style.backgroundColor="#eefaff";
		ss.style.color= "#000000";
	}
	var vv = document.sint.ss.value;
	sse(vv);
	
	var vv2 = document.sint.ss2.value;

	if(vv == vv2)
	{
		vv2 = parseInt(vv)+1;	
		if(vv2 == 5)
			vv2 = 1;
		document.sint.ss2.value = vv2;
	}
	sse(vv2);
}

function sse(vv){
	var dd = "document.sint.res"+vv;
	ss = eval(dd);
	ss.disabled=true;
	ss.value="";
	ss.style.color= "black";
	ss.style.backgroundColor="#bbc7dd";
}

function color(test)
{
	var myI=document.getElementsByTagName("input").item(4);
	myI.style.backgroundColor=test;
}


function color1(test)
{
var myI=document.getElementsByTagName("table").item(0);
//myI.setAttribute("style",ch);
myI.style.backgroundColor=test;
}