Problem in AutoSuggest placeholder text change

Problem in AutoSuggest placeholder text change

When page first time loads in mozilla or firefox it working fine for change placeholder text but when we refresh the page with F5 keyboard our placeholder text is not working its behaves like text in placeholder.however i am changing placeholder with onchange of select box id based.but the same thing working fine in chrome.


html i have used for autosuggest box is below:

<FORM NAME="searchForm" ONSUBMIT="return CheckDataSearch(document.searchForm);" METHOD="post" STYLE="margin:0px;" action="">
<div class="q_srb1">
<input class="q_txb" name="ss" id="ss" value="">
<select size="1" name="searchfor" class="q_slb" id="select">
<option value="offer" selected>Sell Offers</option>
<option value="leads">Buy Leads</option>
<option value="product">Products</option>
<option value="comp">Suppliers</option>
<option value="tenders">Tenders</option></select>
<INPUT TYPE="hidden" NAME="search" VALUE=""><INPUT TYPE="hidden" NAME="modid" VALUE=""><INPUT TYPE="hidden" NAME="cr" VALUE=""><INPUT TYPE="hidden" NAME="sr" VALUE=""><input value="" class="q_btn" type="SUBMIT" id="btnSearch"></div>
</FORM>
</div>

Suggester  object i am using shown below:
new Suggester({"element":"ss", "highlight":"normal", "onSelect":selecttext, "placeholder":"Enter Product / Service Offers to Search ...", "classPlaceholder":"ui-placeholder-input"});


can anybody help me resolve the issue