validation of two or more number fields in form

Question

<script language = "Javascript">
  function ValidateForm()
{
    var fname=document.frmSample1.name
    var address=document.frmSample1.address
    var mark1 =document.frmSample1.mark1 
    var mark2 =document.frmSample1.mark2
    var mark3 =document.frmSample1.mark3
    if ((fname.value==null)||(fname.value==""))
        {
           alert("Please Enter username")
           return false
        }
    if ((address.value==null)||(address.value==""))
        {
           alert("Please Enter address")
           return false
        } 
    if ((mark1.value==null)||(mark1.value==""))
        {
           alert("Please Enter mark1")
           return false
        } 
     if ((mark2.value==null)||(mark2.value==""))
        {
           alert("Please Enter mark2")
           return false
        } 
         if ((mark3.value==null)||(mark3.value==""))
        {
           alert("Please Enter mark3")
           return false
        } 
    if ((mark1.value!=null)||(mark1.value!=""))

        {
              if(isNaN(mark1.value))
              {
              alert('please enter correct mark1');
              return false
              }
              else
              return true
        }

    if ((mark2.value!=null)||(mark2.value!=""))

        {
              if(isNaN(mark2.value))
              {
              alert('please enter correct mark2');
              return false
              }
              else
              return true
        }
    if ((mark3.value!=null)||(mark3.value!=""))

        {
              if(isNaN(mark3.value))
              {
              alert('please enter correct mark3');
              return false
              }
              else
              return true
        }
}  
</script>
    </head>
    <body>
    <form method="post" action="" enctype="multipart/form-data" name="frmSample1" onSubmit="return ValidateForm()" >
                  name:<input type="text" name="name" value=""><br><br>
                  address:<input type="text" name="address" value=""><br><br>
                  image:&nbsp;&nbsp;<input type="file" name="file" id="file"><br><br>
                  mark1:<input type="text" name="mark1" value=""><br><br>
                  mark2:<input type="text" name="mark2" value=""><br><br>
                  mark3:<input type="text" name="mark3" value=""><br><br>

                 <input type="submit" name="submit" value="submit">

                </form>

    </body>
</html>

This form contains three marks fields. I want to validate whether the three mark fields are entered by the numbers or not.The given code is checking only the first mark is number or not.

This form contains three marks fields. I want to validate whether the three mark fields are entered by the numbers or not.The given code is checking only the first mark is number or not.

This form contains three marks fields. I want to validate whether the three mark fields are entered by the numbers or not.The given code is checking only the first mark is number or not.

Answer 1

You need to remove the:

return true

Using return stops execution of the function.