提交表格中添加button后自动提交问题

<form action="{p1::U('News/index')}" method="post" id="form" name="form"><p><div id="preview"></div></p><p class="tit">您的姓名</p><p><input name="username" type="text" class="wenbenkuang" size="30" maxlength="16"></p><p class="tit">联系方式</p><p><input name="contact" type="text" class="wenbenkuang"  size="30" maxlength="100"></p><p class="tit">事件描述</p><p><textarea name="comments" cols="37" rows="11" style="width:97%;height:200px;font-size:16px;"></textarea></p><p class="tit">我的位置（如不确定，可点击我在哪儿）</p><p><input name="address" type="text" class="wenbenkuang" id="address" size="30" maxlength="100"></p><p><button class="btn2" id="getLocation" >我在哪儿</button></p><p><input type="submit" value="提交" name="tijiao"></p></form>

	wx.ready(function () {  document.querySelector('#getLocation').onclick = function () {    wx.getLocation({    	type: 'gcj02',      success: function (res) {        // alert(JSON.stringify(res));        var lat = res.latitude;        var lng = res.longitude;        var latLng = new qq.maps.LatLng(lat, lng);           geocoder = new qq.maps.Geocoder({             complete: function (result) {                      signin_info = result.detail.addressComponents.province + result.detail.addressComponents.city                                    + result.detail.addressComponents.district + result.detail.addressComponents.street;                       $("#address").val(signin_info);                       }                   })                   geocoder.getAddress(latLng);               },     	 	cancel: function (res) {       				 alert('用户拒绝授权获取地理位置');      }    });  };