function insertTag(textareaID, formatTag, attribute) {
  var sel;
  var textarea = document.getElementById(textareaID);
  var tagStart = formatTag;
  var tagEnd = formatTag;

  //ff
  if(textarea.selectionStart || textarea.selectionStart=='0') {
    var startPos = textarea.selectionStart;
  var endPos = textarea.selectionEnd;
  var cursorPos = endPos;
  var scrollTop = textarea.scrollTop;

  if(startPos != endPos){
    textarea.value = textarea.value.substring(0,startPos)
               + formatTag
               + textarea.value.substring(startPos,endPos)
               + formatTag
               + textarea.value.substring(endPos,textarea.value.length);
      cursorPos += formatTag.length + formatTag.length;
    }else{
    textarea.focus();
    textarea.selectionStart = cursorPos;
    textarea.selectionEnd = cursorPos;
    textarea.scrollTop = scrollTop;
  }
  //ie
  }else if(document.getSelection){
    textarea.focus();
  sel=document.getSelection();
  }else if (document.selection) {
    sel = document.selection.createRange();
    if(sel.text.length > 0){
    sel.text = formatTag + sel.text + formatTag;
  }else{
    textarea.value += formatTag + ' ' + formatTag;
    textarea.focus();
  }
  }
}

function insertURL(textareaID, url, urltitle) {
  var textarea = document.getElementById(textareaID);
  
  textarea.value += '"'+urltitle+'":'+url;
  textarea.focus();
}

function format(type, textarea) {
  
  if(!textarea){
    textarea = 'post';
  }

  if(type=='bold'){
  insertTag(textarea,'*',' ');
  }

  if(type=='italic'){
  insertTag(textarea,'_',' ');
  }

  if(type=='url'){
    var url = prompt("Hver er slóðin","http://www.");
    
  if(url!=null && url!=''){
    var urltitle = prompt("Og nafnið á síðunni er?","");
    if(urltitle!=null){
      insertURL(textarea, url, urltitle);
    }
  }
  }
  mode('edit');
}

function mode(type){
  if(document.getElementById('editor-mode')){
  var modebutton = document.getElementById('editor-mode');
  var previewdiv = document.getElementById('postdisplay');
  var contentdiv = document.getElementById('post');

    if(type=="edit"){
    modebutton.className = "btn-mode preview";
    modebutton.href="javascript:mode('preview');";
    
    previewdiv.style.display = "none";
    contentdiv.style.display = "block";
    contentdiv.focus();
  }
  
  if(type=="preview"){
    modebutton.className = "btn-mode edit";
    modebutton.href="javascript:mode('edit');";
    
    previewdiv.innerHTML = publishText(contentdiv.value);
    
    previewdiv.style.display = "block";
    contentdiv.style.display = "none";
  }
  }else{
  return;
  }
}

function resizeTextArea(type, textareaID){
  if(!textareaID){
    textareaID = 'post';
  }
  
  if(document.getElementById(textareaID)){
    var textarea = document.getElementById(textareaID);
    var previewdiv = document.getElementById('postdisplay');
  
  var numsizes = 4;
  var minheight = "100px";
  var maxheight = "520px";
  var currheight = textarea.style.height;
  
  var size01 = minheight;
  var size02 = "260px";
  var size03 = "390px";
  var size04 = maxheight;
     
    if(type=="increase"){
    var newheight = size02;
    if(currheight == size01){
      newheight = size02;
    }else if(currheight == size02){
      newheight = size03;
    }else if(currheight == size03){
      newheight = size04;
    }else if(currheight == size04){
      newheight = maxheight;
    }
    textarea.style.height = previewdiv.style.height = newheight;
    }
  
    if(type=="decrease"){
        var newheight = size01;
    if(currheight == size01){
      newheight = minheight;
    }else if(currheight == size02){
      newheight = size01;
    }else if(currheight == size03){
      newheight = size02;
    }else if(currheight == size04){
      newheight = size03;
    }
    textarea.style.height = previewdiv.style.height = newheight;
    }
  
  }
}