Javascript function to check valid decimal value with specified digits after decimal point

    Below is the function that validates only positive decimal numbers in text box. You can specify number of digits that can be allow after decimal point.

 

var DigitsAfterDecimal = 8;
function CheckUnit()
    {
        
        if(document.getElementById
            ("TextBoxName").value == '' )
        {
            alert("Please enter valid decimal 
            value");
            return false;
        }
        else
        {
            
           if(isNaN(document.getElementById
               ("TextBoxName").value))
           {
                alert("Please enter valid decimal 
                value");


                return false;
           }
           else
           {
                var val = document.getElementById
                    ("TextBoxName").value;
                if(val.indexOf(".") > -1)
                {
                    
                    if(val.length - (val.indexOf
                        (".")+1) > 
                           DigitsAfterDecimal)
                    {
                        alert("Please enter valid 
                          decimal value. Only " +
                          DigitsAfterDecimal + " 
                         digits are allowed after 
                         decimal.");



                         return false;
                    }
                    else
                    {
                      return true;
                    }
                }
                else
                {
                    if(parseInt(val) > 0)
                    {
                        return true;
                    }
                    else
                    {
                       alert("Value must be 
                       greater than 0"); 

                       return false;
                     }
                }
           }
        }
    }

Happy Programming !!