alphanumeric range Validation

[raj kumar]

hi,
i am trying to run a simple html page with a java script validation for range validation

i have two text fields in which user enters two alphanumeric values
i have to validate if the first value is less than second or not.
when i click on submit i am getting "document.id.value" is null or not an
object

my function is

   function ValidateRange() {
    
        var i;
        
        if (document.fromId.length < 1)
//        if (document.fromId.value == "")
        {
        alert("Please enter a from Id.");
        return;
        }
 
        if (document.toId.value == "")
        {
        alert("Please enter a to Id.");
        return;
        }
 
        for( i =0; i < document.fromId.length; i++)
        {
            if (document.fromId[i].value > document.toId[i].value)
            {
            alert('From Id should be smaller than To Id');
            return;
            }
        }
} 

how to fix this...
thanks

[Eric Pascarello]

document.FormName.ElementName.value

plus

...value > ...value is comparing strings you need to use parseFloat if it is numbers.

Eric

[raj kumar]

thanks
i have changed to use the form name and field names...

but the values of ids i have is alphanumeric, so i have to compare for the string part of it and then the integer part of it.

like if i have from "bc1" to "cd4" then i have to first compare if b<c which is true and also if they are "bc1" and "bc2" then also its true as here 1<2 but if they are like "bc1" and "ac2" then it is false as b>a ...
hope i am clear?

thanks,

[Balan Raj]

Raj,

Looks like you need to write your own comparison routine to validate this since this is a pretty unique case.
what is the logic for the following cases
12BAR & BAR12
or AB124 & ABC12
& what if they have strings of varying lengths ??

First u need to validate if they are valid alpha-numeric characters ( a simple search wud give you free examples) & then get one character from each & continue your check using

  charAt(i)  

HTH