How to validate all text fields from form using javascript?

// order_content_node it is an form name

function validateAllTextfields()
{ 
      for(i=0; i<document.order_content_node.elements.length; i++)
     {
            element = document.order_content_node.elements[i];
            if (element.type == 'text')
           {
                if(element.value == '')
                {
                        alert("One or more fields were left blank.");
                        return false;
                 }
                 else if (!element.value.match('[0-9]'))
                {
                       alert("Please enter valid value");
                       return false;
                 }
                //alert("The field name is: " + element.name + " and it’s value is: " + element.value);
          } 
       }
return true;
}