title: how to restrict number field to enter only numbers in oracle apex
body: <p>I'm new to oracle apex. Currently I'm working on oracle apex 5.0. I've created an item of type number field. I want this field for entering mobile number. So, I used format masking like '9999999999'.<BR>
  Now problem is, after executing that application I can able to enter alphabets also. For now, I made a validation on it, but I want my item to accept only number as input. User can't be able to add any alphabets in it.<br>
  I've also tried, putting <code>input type="tel" maxlength="10"</code> and <code>input type="number" max="10"</code> this code in my <code>HTML Form Element Attributes</code> field as well as <code>HTML Form Element CSS Classes</code> field but it doesn't work.<BR>
  <BR>
  No matter which query I put in <code>HTML Form Element Attributes</code> it will result in problem which is shown in image <a href="https://i.stack.imgur.com/5KRSJ.png" rel="nofollow noreferrer"><strong>Problem with HTML Form Element Attributes</strong></a>.Now, as you can see in that image, this time I've added  <code>&lt;input type="tel" maxlength=10 pattern="[0-9]{3}-[0-9]{3}-[0-9]{4}"&gt;</code> this statement, but having that same problem.<BR>
  Now I also tried to put that statement into <code>HTML Form Element CSS Classes</code>, and here that problem is not appearing but still I'm able to add alphabets in it. </p>
  
  <p>Please guide me how to do that.</p>