javasript Is there a limit to else if statements

I am getting value from a text field. I have one if and several else if statement.

The problem the last else if doesn't execute even if the condition is true.

If I change the last else if to if it executes and gives alert. When i change that back to else if the statement doesn't execute. The else if before that is fine as it's firing/executing on a particular condition.

function Valcheck()

{



var txtVal = document.getElementById("sometextField").value;







if(txtVal =="%") 

    {



        alert("% is only allowed with other characters.");

        return;

    }       



    else if(txtVal.indexOf("%") != -1) 

    {

        if((txtVal.indexOf('%')) != (txtVal.length-1)) 

        {

            alert(" % is only allowed at the end.");

            return;

        }       

    } 

    else if(txtVal.indexOf(",") != -1) 

    {

        alert("Comma or comma separated values are not allowed.");

        return;



    } 

    else if(( txtVal.length  >0) &&  (txtVal.indexOf("%") == -1)) 

    {

        alert("Please enter % at the end of the value.");

        return;

    }            



    else if( txtVal.length > 11 ) 

    {



        alert(" Value can't be greater than 11 characters.");

        return;



    }



}

Please help. Thanks