function showcredit()

{



var credit

credit=   "June 2002   Script programmed by Jens T.Saetre "



credit+="\n08122002 Changed layout"

window.alert(credit);

}





function calculate_angle(){

var toRad,toDeg,pi,distance,height,angle



toRad=Math.PI/180;

toDeg=180/Math.PI;



distance=1*document.Elevation.Distance.value;

height=1*document.Elevation.Height.value;

angle=toDeg*Math.atan(height/distance);

document.Elevation.Angle.value=formatvalue(angle,4);





}





function On_angle_change(){   //***Caøculate the new height****

var toRad,toDeg,pi,distance,height,angle



toRad=Math.PI/180;

toDeg=180/Math.PI;

angle=1*document.Elevation.Angle.value;

distance=1*document.Elevation.Distance.value;

height=Math.tan(toRad*angle)*distance;



document.Elevation.Height.value=formatvalue(height,5);



}





function formatvalue(input, rsize) // Desimal avrunding

  {

   var invalid = "**************************";

   var nines = "999999999999999999999999";

   var strin = "" + input;

   var fltin = parseFloat(strin);

   if (strin.length <= rsize) return strin;

   if (strin.indexOf("e") != -1 ||

       fltin > parseFloat(nines.substring(0,rsize)+".4"))

      return invalid.substring(0, rsize);

   var rounded = "" + (fltin + (fltin - parseFloat(strin.substring(0, rsize))));

   return rounded.substring(0, rsize);

}