Custom select box drop down inside a table cell in HTML/CSS - html

Question

I have kept a Custom select box in a Table Td cell, which when clicked opens a list of two custom options. Adding a row to the table creates another instance of the same Custom select box whose functionality is same as above.
<div class="multiselect">
<div class="InternetselectBox" id="Connectivity_COld9_InternetFacilityDiv_1" onclick="showInternetLocationCheckboxes(this)">
<select class="location_select" style="color: #666;" id="Connectivity_COld9_InternetFacility_1">
<option value="0"> 2 Location Selected</option>
</select>
<div class="overSelect"></div>
</div>
<div class="MultiSelect_checkboxes InternetMultiSelect" id="Connectivity_COld9_MultiSelect_checkboxes_1" style="display: block;">
<label for="Connectivity_COld9_InternetFacilityCHK_1_1">
<input type="checkbox" checked="checked" id="Connectivity_COld9_InternetFacilityCHK_1_1" name="lineup[]" onclick="InternetDynamicCheckboxCount(this)">
TCO
</label>
<label for="Connectivity_COld9_InternetFacilityCHK_1_2">
<input type="checkbox" checked="checked" id="Connectivity_COld9_InternetFacilityCHK_1_2" name="lineup[]" onclick="InternetDynamicCheckboxCount(this)">
MEPS
</label>
</div>
</div>
The issue is, when I click on the select box, and scroll the page or that particular div(table div), the drop down menu also moves along with the scrolling direction. I have a little bit of confusion with using Css style of Position
And when I add row and scroll down, the drop down also moves along.
Help me in resolving this issue. I want a drop down to appear just when I click the drop down and not move when I scroll down or up.
I tried to use css property position: relative to the drop down. But, it displaces or expands other Td of the same row. I do not need this.
Any css class needs to be added. Let me know. Any help is appreciated.