[Vlasenko Fedor]

Попытка №2

<style>
      div.testblock {
        width:200px;
        margin: 10px;
        float: left;
      }
      div.testblock>textarea {
        width:200px;
        height: 80px;
        clear:booth;
      }
    </style>
    <div class="testblock">
      <textarea></textarea>
      <div id="panel">
        <input type="button" value="A" />
        <input type="button" value="B" />
        <input type="button" value="C" />
        <input type="button" value="D" />
        <input type="button" value="E" />
      </div>
    </div>
    <div class="testblock">
      <textarea></textarea>
    </div>
    <div class="testblock">
      <textarea></textarea>
    </div>
    <script>
      window.onload = function () {
        var inps = document.querySelectorAll("div.testblock"),
          len = inps.length;
        for (; inps[--len].setAttribute("onclick", "edit(this)"), len;);
      }
      edit = function (el) {
        el.appendChild(panel);
      }
      panel.onclick = function (e) {
        e = e || window.event;
        var el = e.target || e.srcElement;
        if (el.tagName != "INPUT") return;
        var par = this.parentNode || this.parentElement,
          tar = par.children[0];
        var myValue = el.value,
          myValueLen = myValue.length;
        if (document.selection) {
          tar.focus();
          var sel = document.selection.createRange();
          sel.text = myValue;
          tar.focus();
        } else if (tar.selectionStart || tar.selectionStart == '0') {
          var startPos = tar.selectionStart,
            endPos = tar.selectionEnd,
            scrollTop = tar.scrollTop;
          tar.value = tar.value.substring(0, startPos) + myValue + tar.value.substring(endPos, tar.value.length);
          tar.focus();
          tar.selectionStart = startPos + myValueLen;
          tar.selectionEnd = startPos + myValueLen;
          tar.scrollTop = scrollTop;
        } else {
          tar.value += myValue;
          tar.focus();
        }
      }
    </script>