textarea 光标插入

<textarea id='target_area'onclick="setCaret(this);" onkeyup="setCaret(this);"></textarea>

//设置textarea光标位置function setCaret(textObj){if(textObj.createTextRange){     textObj.caretPos=document.selection.createRange().duplicate();  }}//光标位置插入内容function insertAtCaret(textFeildValue){var textObj = document.getElementById('target_area');if(firefox){var start = textObj.selectionStart;var end = textObj.selectionEnd;textObj.value = textObj.value.substr(0,start) + textFeildValue + textObj.value.substr(end);}    else{if(textObj.createTextRange && textObj.caretPos){     var caretPos=textObj.caretPos;    caretPos.text=caretPos.text.charAt(caretPos.text.length-1)==''?textFeildValue+'':textFeildValue;}else {  textObj.value+=textFeildValue;}}}