How to create a minLength validator?

Suite and Optimus Suite 5
#1

Hello again…

How to create a minLength function to control the characters in a field?
maxLenth exists, but minLength?

The XML

<item type="input" name="username" label="Username" inputWidth="150" required="true" validate="ValidNumeric" maxLength="6"/>
#2

This is my script

var myForm;
            function doOnLoad() {
		myForm = new dhtmlXForm("formDataAndFees");
                myForm.loadStruct("data.php");
                myForm.attachEvent("onButtonClick", function(name) {
                    window[name]();
                });
                
                myForm.attachEvent("onAfterValidate", function(status){
                    if (status == true) {
                        myForm.send("data.save.php", "post", sendCallback, true);
                    }
                });
            }
            
            // Validation
            function doFormValidate() {
                myForm.validate();
            }
            
            // Callback function for send
            function sendCallback(r) {
                document.location = "form.php?step=2";
            }
#3

Hello
There is no native approach
You can try to use something like

validate: function(v){return String(v).length>=3;}