使用 radio 時, 想讓滑鼠點到 input box 時自動去切換

<form action="smssent.asp" method="post" name="smssentform" OnSubmit="return checkinput(this,'add');">
<input type="radio" name="whensent" value="asap" checked><label class="normalFont">馬上傳送</label></nobr>
<input type="radio" name="whensent" value="setdate"><label class="normalFont">
西元<input type="text" name="wyear" maxlength="4" class="recTextbox" value="<%=year(now)%>" onclick="smssentform.whensent[1].click();">年<input type="text" name="wmonth" maxlength="2" class="recTextbox" value="<%=month(now)%>" onclick="smssentform.whensent[1].click();">月<input type="text" name="wday" maxlength="2" class="recTextbox" value="<%=day(now)%>" onclick="smssentform.whensent[1].click();">日</label></nobr>