onload=function() {

var divh = document.getElementById('page').offsetHeight;

// document.getElementById('left').style.height = divh + "px";
 //document.getElementById('center').style.height = divh + "px";
// document.getElementById('right').style.height = divh + "px";
}


function enterNumber(id){

  var e = document.getElementById(id);

  if (!/^[0-9]+$/.test(e.value)) { 
    alert("Prosím, zadávejte pouze číselné hodnoty.");
    e.value = e.value.substring(0,e.value.length-1);
  }
}   


function zobraz_odkaz(id){

  var menu = document.getElementById("print_menu").style;

  if (id == 0) { 
    menu.display = "none";
  } else {
    menu.display = "block";
  }
}  


function print_content(oldfilename, newfilename, filetype){

 var targetattr = "href" ;
 var allsuspects = document.getElementsByTagName("link");
 
 for (var i = allsuspects.length; i >= 0; i--){ 
  if (allsuspects[i] && allsuspects[i].getAttribute(targetattr) != null && allsuspects[i].getAttribute(targetattr).indexOf("/styl.css") != -1){
   
   var newelement = document.createElement("link")
   newelement.setAttribute("rel", "stylesheet")
   newelement.setAttribute("type", "text/css")
   newelement.setAttribute("href", "/print.css")
  
   allsuspects[i].parentNode.replaceChild(newelement, allsuspects[i])
  }
 }
 
 window.print();
  
 var targetattr = "href" ;
 var allsuspects = document.getElementsByTagName("link");
 
 for (var i = allsuspects.length; i >= 0; i--){ 
  if (allsuspects[i] && allsuspects[i].getAttribute(targetattr) != null && allsuspects[i].getAttribute(targetattr).indexOf("/print.css") != -1){
   
   var newelement = document.createElement("link")
   newelement.setAttribute("rel", "stylesheet")
   newelement.setAttribute("type", "text/css")
   newelement.setAttribute("href", "/styl.css")
  
   allsuspects[i].parentNode.replaceChild(newelement, allsuspects[i])
  }
 }
}