//设置表情

//str  新添加的字符串

function shezhiBq(str)

{

var obj = document.getElementById("rl_exp_input");//获取文本框

obj.focus();

if (document.selection) {

var sel = document.selection.createRange();  

sel.text = str;

alert('a');

} else if (typeof obj.selectionStart == 'number' && typeof obj.selectionEnd == 'number') {

var startPos = obj.selectionStart,

endPos = obj.selectionEnd,

cursorPos = startPos,

tmpStr = obj.value;

obj.value = tmpStr.substring(0, startPos) + str + tmpStr.substring(endPos, tmpStr.length);

var jj=tmpStr.substring(0, startPos) + str;  //当新字符串添加后的光标位置

obj.selectionStart =  obj.selectionEnd =jj.length; //设置新光标位置在新添加字符串的后面

alert(obj.selectionStart);

} else {

obj.value += str;

}

}