text: function changeFontFamily() {
      let text = document.getElementById("text");
      let z = document.getElementById("font_family");
      text.style.fontFamily = z.value;
  }
  
  function changeFontSize() {
      let text = document.getElementById("text");
      let x = document.getElementById("font_size");
      text.style.fontSize = x.value;
  }
  
  function changeFontItalic() {
      let text = document.getElementById("text");
      let i = document.getElementById("font_italic").checked;
      text.style.fontStyle = (i ? "italic" : "normal");
  }
  
  function changeFontBold() {
      let text = document.getElementById("text");
      let b = document.getElementById("font_bold").checked;
      text.style.fontWeight = (b ? "bold" : "normal");
  }
  
  function changeFontUnderline() {
      let text = document.getElementById("text");
      let u = document.getElementById("font_underline").checked;
      text.style.textDecoration = (u ? "underline" : "none");
  }
  