取得input中部分选中(selected)的值

取得input中部分选中(selected)的值（for IE and Firefox），这个例子非常不错，给大家共享一下。

<script language="javascript">

var agt=navigator.userAgent.toLowerCase();

var ie = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1) && (agt.indexOf("omniweb") == -1));

function a(){

var myArea = document.getElementById("s");

var selection;

if (!ie){

if (myArea.selectionStart!= undefined) {

selection = myArea.value.substr(myArea.selectionStart, myArea.selectionEnd - myArea.selectionStart);

}

}else{

if (window.getSelection){

selection = window.getSelection();

}else if (document.getSelection){

selection = document.getSelection();

}else if (document.selection){

selection = document.selection.createRange().text;

}

}

alert(selection)

}

</script>

<input type="text" value="testtest" id="s" name="s"

onmouseup="javascript:a()" />