$("select[name='e']").change(function(){
var option_index=this.selectedIndex //获取Select选择的索引
var select_value=$(this).val() //获取Select选择的Valu
var select_text=$(this).find("option:selected").text() //获取Select选择的Te
alert("获取Select选择的索引值:"+option_index+" 获取Select选择的Value:"+select_value+" 获取Select选择的Text:"+select_text)
})
$("#select_id option[text='后来']").attr("selected", true); //设置option selected为true
<form action="">
<input type="text" value="kill" />
<button name="bt" value="bt" >fg</button>
<select name="e">
<option value="5" >从前</option>
<option value="6">可是</option>
<option value="7">后来</option>
</select>
<input type="submit" value="submit"/>
</form>