function NullToZero(x){
	if(x==null || x=="")
		x=0;
}

function ClearForm(form) {

	for (var i = 0; i < form.length; i++) {
		if (form[i].type == "text")
		    form[i].value = "";
	}
    return true;

}

function CalcLen(form){

	var mm, cm, m, inch, ft;

	mm = form.mm.value;
	cm = form.cm.value;
	m = form.m.value;
	inch = form.inch.value;
	ft = form.ft.value;
	
	if (mm != "") {
	   cm = mm * 0.1;
	   m = mm * 0.001;
	   inch = mm * 0.0393700787;
	   ft = mm * 0.0032808399;

	} else {
	
		if (cm != "") {
	   		mm = cm * 10;
	   		m = cm * 0.01;
	   		inch = cm * 0.393700787;
	   		ft = cm * 0.032808399;

		} else {

			if (m != "") {
	   			mm = m * 1000;
	   			cm = m * 100;
	   			inch = m * 39.3700787;
	   			ft = m * 3.2808399;

			} else {

				if (inch != "") {
		   			mm = inch * 25.4;
		   			cm = inch * 2.54;
	   				m = inch * 0.0254;
	   				ft = inch / 12;

				} else {

					if (ft != "") {
			   			mm = ft * 304.8;
			   			cm = ft * 30.48;
	   					m = ft * .3048;
	   					inch = ft * 12;	
					
					} else
			   			window.alert("do nothing");
				}
			}
	    }
	}	   

	//Math.round(test*1000)/1--0; // rounds to the thousandths decimal
	
	form.mm.value = Math.round(mm*1000)/1000;
	form.cm.value = Math.round(cm*1000)/1000;
	form.m.value = Math.round(m*1000)/1000;
	form.inch.value = Math.round(inch*1000)/1000;
	form.ft.value = Math.round(ft*1000)/1000;

}

function CalcWeight(form){

	var kg, g, lbs, oz;

	kg = form.kg.value;
	g = form.g.value;
	lbs = form.lbs.value;
	oz = form.oz.value;
	
	if (kg != "") {
	   g = kg * 1000;
	   lbs = kg * 2.20462262;
	   oz = kg * 35.2739619;

	} else {
	
		if (g != "") {
	   		kg = g / 1000;
	   		lbs = g * 0.00220462262;
	   		oz = g * 0.0352739619;

		} else {

			if (lbs != "") {
	   			kg = lbs * 0.45359237;
	   			g = lbs * 453.59237;
	   			oz = lbs * 16;

			} else {

				if (oz != "") {
		   			kg = oz * 0.0283495231;
		   			g = oz * 28.3495231;
   					lbs = oz / 16;
					
				} else
		   			window.alert("do nothing");
			}
	    }
	}	   

	//Math.round(test*1000)/1--0; // rounds to the thousandths decimal
	
	form.kg.value = Math.round(kg*1000)/1000;
	form.g.value = Math.round(g*1000)/1000;
	form.lbs.value = Math.round(lbs*1000)/1000;
	form.oz.value = Math.round(oz*1000)/1000;

}

function CalcTemp(form){

	var f, c;

	f = form.f.value;
	c = form.c.value;
	
	if (f != "") {
	   c = (f - 32) / 1.8;

	} else {
	
		if (c != "") {
	   		f = c * 9/5 + 32;
							
		} else {
	 		window.alert("do nothing");
		}
	}	   

	//Math.round(test*1000)/1--0; // rounds to the thousandths decimal
	
	form.f.value = Math.round(f*1000)/1000;
	form.c.value = Math.round(c*1000)/1000;

}