JSFiddle - React, Tailwind, and code Playground

HTML

<input id="textbox1" type="text" /><input type="button" id="btn" value="validate" />

JavaScript

String.prototype.Contains = function (str) {  

  var mychar;
  for(var i=0; i<str.length; i++)
  {
    mychar = this.substr(i, 1);
    if(str.indexOf(mychar) == -1)
    {
        return false;
    }
  }

  return this.length > 0;
};
    
window.onload = function(){
  

    document.getElementById("btn").onclick = function(){
          var chars = "0123456789";
          if(document.getElementById("textbox1").value.Contains(chars))
          {
              alert("valid");   
          }
          else
          {
              alert("invalid");   
          }
    };

};