findPrime.cfm

<cfsetting requesttimeout="500">
<form action="isprime.cfm" method="post">
    Find Primes out to <input type="text" name="myNum" value="">
    <input type="submit" value="Find Primes">
</form>

<cfif structKeyExists(form,"myNum")>
    <table>
    <tr>
        <td colspan="10">
            Finding Prime Numbers from 1 to <cfoutput>#form.myNum#</cfoutput>
        </td>
    </tr>
    <br>
    <cfset count = 0>
    <tr>
    <cfloop index="p" from="1" to="#myNum#" step="1">
        <cfif isPrime(p)>
            <td><cfoutput>#p#&nbsp;</cfoutput></td>
            <cfset count = count + 1>
            <cfif count mod 10 eq 0>
                </tr><tr>
            </cfif>
        </cfif>
    </cfloop>
    </table>
</cfif>

<cfscript>
    public boolean function isPrime(required numeric myNum ) {
        if (myNum < 2) {return false;}
        if (myNum == 2) {return true;}
        if (myNum % 2 == 0) {return false;}
        for ( i = 2; i * i <= myNum; i++){
            if (myNum % i == 0) return false;
        }
        return true;
    }
</cfscript>