function isNumeric(sText) {   
   var ValidChars="0123456789.";
   var Char;
   var isNum=1;
   for (i = 0; i < sText.length && isNum == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         isNum = false;
         }
      }
   return isNum;
 }
 function checkTel(id) {
   var pocetVal = document.getElementById(id);
   var val=pocetVal.value;
   var num=false;
   num=isNumeric(val);
   //if (!num) alert('zadejte číslo');
   return true;    
   //return num;
 }
 function odeslatProd(prod) {
  var pocetVal = document.getElementById("pocetVal");
  var val=pocetVal.value;
  var num=false;
  num=isNumeric(val);
  if (!num) alert('zadejte číslo');    
  return num; 
 }
 function pocetPlus() {
  var pocetVal = document.getElementById("pocetVal");
  var cenaVal = document.getElementById("cenaVal");
  var cenaTotal = document.getElementById("cenaTotal");
  pocetVal.value++;  
  if (!isNumeric(pocetVal.value)) pocetVal.value=1;
  cenaTotal.value=(cenaVal.value)*pocetVal.value; 
 }
 function pocetMinus() {  
  var pocetVal = document.getElementById("pocetVal");
  var cenaVal = document.getElementById("cenaVal");
  var cenaTotal = document.getElementById("cenaTotal");
  if (pocetVal.value>0) {
   pocetVal.value--;   
  }  
  if (!isNumeric(pocetVal.value)) pocetVal.value=1;
  cenaTotal.value=(cenaVal.value)*pocetVal.value;
 }
 function posunGal() {    
  picStart=galInd;
  picNow=picStart      
  for (n=1;n<12;n++) {
   picNow=picStart+n-1;
   if (picNow>=max || picNext[picNow]==null) {   
    picNow=0;
    picStart=1-n;
    galInd=-6;    
   }      
   var mImg = document.getElementById(""+n);
   var file=picNext[picNow];
   mImg.src="/loadFile.php?fn="+file;   
   //mImg.onclick=loadImgSrc('"+picNextFile[picNow]+"',"+n+");
   mImg.onclick = new Function(" loadImgSrc('"+picNextFile[picNow]+"','"+n+"')   ");
  }
  galInd+=6;
 } 
 function loadImgSrc(file,n) {
  var mImg = document.getElementById('imgEnl');
  var infoP = document.getElementById('infoP');
  infoP.innerHTML="Obrázek se zavře kliknutím na něj.";
  mImg.className='imgIsEnl';
  mImg.src="/loadFile.php?fn="+file; 
 }
 function loadImgSrc2(file,n) {
  var mImg = document.getElementById('imgEnl');
  var infoP = document.getElementById('infoP');
  infoP.innerHTML="Obrázek se zavře kliknutím na něj.";
  mImg.className='imgIsEnl';
  mImg.src="/loadFile.php?fn="+file; 
 }
 function hideImg() {
  var mImg = document.getElementById('imgEnl');
  var infoP = document.getElementById('infoP');
  infoP.innerHTML="";
  //mImg.className='imgNotEnl';
  mImg.src="";
 }