เงื่อนไขการ show/hide textbox มาให้กรอกข้อมูล ในการ clone หลายแถว

<script language="JavaScript">
$(document).ready(function(){
    $("#addRow").click(function(){
        var html = $(".tramount:last").html();
        var last_id = parseInt($(".tramount:last").attr("id").split("_")[1]);
        var new_id = last_id+1;
        var newRow = '<tr class="tramount" id="tramount_'+new_id+'">'; 
        newRow += html.replace(new RegExp("_"+last_id,"g"), "_"+new_id);
        newRow += "</tr>";
        $("#tblamount tbody").append(newRow);
    });
    $("#removeRow").click(function(){
        if($(".tramount").length > 1) $(".tramount:last").remove()
    });
    $('input[name="cost[]"], input[name="amount[]"]').change(function(){
        var total = 0.0;
        $(".tramount").each(function(){
            var now_id = parseInt($(this).attr("id").split("_")[1]);
            var cnt = parseInt($("#amount_"+now_id).val());
            var price = parseFloat($("#cost_"+now_id).val());
            var row = (cnt*price);
            if(row!= NaN && row>0) total += row;            
        });
        $("#sum").val(total);        
    });
});
</script>

<script language="javascript">
$(document).ready(function() {
	$('#rentPrice').hide(); //hide field on start
 
	$('#type_1').change(function() {
 
	 var $index = $('#type_1').index(this);
 
	 if($('#type_1').val() == 'เช่า') { //if this value is NOT selected
	 $('#rentPrice').show(); //this field is hidden
	 } 
	 else {
	 $('#rentPrice').hide();//else it is shown
 
	 }
        });
 });
</script>