1. Prevent the input of non-numbers, except for backspace
2. Limit the maximum input string length
//Limit the maximum input length
var checkMaxL = function(length) {
var regC = /[^ - ~] /g;
var regE = /D /g;
var str = jQuery("#remark").val();
if (regC.test(str)){
jQuery("#remark").val(str.substring(0, length));
}
if(regE.test(str)){
jQuery("# remark").val(str.substring(0, length));
}
}