jquery ui datepicker没有动态设置

Question

i am trying to set mindate dynamically on pageload event and dropdown change event also , mindate sets in page load but when i am trying to set on change event it gives error this is my code //basic initialization of datepicker

$('#transaction_date').datepicker({
    dateFormat: 'yy-mm-dd',
    changeMonth: true,
    changeYear: true,
    maxDate: 'today',
    inline: true
});

var fy_start_date = '<?php echo $fy_start_date;?>';

// call function to set mindate on pageload 
setmindate(fy_start_date, 0);

// dropdown change event to call ajax function to set ne mindate value
$('#from_ledger').change(function(){
    var accstartdate = $('#from_ledger').val();
    getstartdate(accstartdate);      
});

// dropdown change event to call ajax function to set ne mindate value
$('#to_ledger').change(function(){
        var accstartdate = $('#to_ledger').val();
        getstartdate(accstartdate);      
   });

//ajax function to set new mindate
function getstartdate(id){
//call function to set new mindtae
                  setmindate(result, 1);
               }

//function to set mindate
function setmindate(min_date, change) {

    var minumum_date = min_date;
    $('#transaction_date').datepicker('destroy');
    $('#transaction_date').datepicker('option', 'minDate', minumum_date);

    }
});

it gives error message Error: cannot call methods on datepicker prior to initialization; attempted to call method 'destroy'

jquery version 1.11.1 jquery ui version 1.11.4