设置无法删除的默认文本框值

Question

All values for a text box begin with T-

how do I have a textbox prepopulated with T- where the user cannot remove the T-

Thanks for your help

Answer 1

Try this

<input id="field" type="text" value="T-" size="50" />

JS

var readOnlyLength = $('#field').val().length;

 $('#output').text(readOnlyLength);

$('#field').on('keypress, keydown', function(event) {
    var $field = $(this);
    $('#output').text(event.which + '-' + this.selectionStart);
    if ((event.which != 37 && (event.which != 39))
        && ((this.selectionStart < readOnlyLength)
        || ((this.selectionStart == readOnlyLength) && (event.which == 8)))) {
        return false;
    }
});  

DEMO

Answer 2

Attach the label before the textbox and give textbox left-border to 0px and label right-border to 0px. While getting the value add both the values. hope it helps you.