function getSelectedText() { //该函数代码借用自：http ://www.codetoad.com/javascript_get_selected_text.asp
var txt = "";
if (window.getSelection) {
txt = window.getSelection();
} else if (window.document.getSelection) {
txt = window.document.getSelection();
} else if (window.document.selection) {
txt = window.document.selection.createRange().text;
}
返回txt；
}
