Try this,
$(function() {
$('select').change(function(){
$( "#amount" ).val( $('select').val() + $( "#slider-range" ).slider( "values", 0 ) +
" - "+ $('select').val() + $( "#slider-range" ).slider( "values", 1 ) );
})
$( "#slider-range" ).slider({
range: true,
min: 0,
max: 500,
values: [ 75, 300 ],
slide: function( event, ui ) {
$( "#amount" ).val( $('select').val() + ui.values[ 0 ] + " - "+ $('select').val() + ui.values[ 1 ] );
}
});
$( "#amount" ).val( $('select').val() + $( "#slider-range" ).slider( "values", 0 ) +
" - "+ $('select').val() + $( "#slider-range" ).slider( "values", 1 ) );
});
HTML:
<select name=currency class=f15>
<option value="$" selected>USD</option>
<option value="৳" >BDT</option>
</select>
<p>
<label for="amount">Price range:</label>
<input type="text" id="amount" style="border:0; color:#f6931f; font-weight:bold;">
</p>
<div id="slider-range"></div>