Speed Radar help

im working on this one speed radar that will update a board but im having trouble asembling the string here is what im trying to do,

if you are under 10 m/s it will say the speed in 05 = 5 m/s ect
and if above it will have it as the 2 digits

im using substrings, any help will be appreciated

key lastSensed;
string display;
string lastSpeed;
string n1 = "";
string n2 = "";
string gsHexChars = "0123456789ABCDEF";
string Int2Hex(integer iInt)
{
    integer iWork = iInt & 0xF;
    string sResult = llGetSubString(gsHexChars, iWork, iWork);
    iInt = (iInt >> 4) & 0x0FFFFFFF;

    while (iInt != 0)
    {
        iWork = iInt & 0xF;
        sResult = llGetSubString(gsHexChars, iWork, iWork) + sResult;
        iInt = iInt >> 4;
    }

    return(sResult);
} // string Int2Hex


string Round2String(float fValue, integer iDecimals)
{
    integer iValue = (integer)fValue;
    integer iRemainder = llRound((fValue - iValue) * llPow(10, iDecimals));

    if (!iRemainder)
    {
        return (string)iValue + ".00";
    }
    else
    {
        return (string)iValue + "." +(string)llAbs(iRemainder);
    }

} // Round2String


string Vector2String(vector vVector, integer iDecimals)
{
    return("<" + Round2String(vVector.x, iDecimals) + ", " +
        Round2String(vVector.y, iDecimals)+ ", " +
        Round2String(vVector.z, iDecimals) + ">");
} // Vector2String


default 
{
    on_rez(integer start_param) 
    {
        llResetScript();
    }
    
    state_entry() 
    {
        llSensorRepeat("", "", AGENT, 10.0, PI/4, 1);
    }
    sensor(integer num_detected) 
    {
        string speed = Round2String(llVecMag(llDetectedVel(0)), 2);
        integer decimalIndex = llSubStringIndex(speed, "");
        speed = llGetSubString(speed, 0, decimalIndex );
        integer newSpeed = (lastSpeed != speed);
        if(speed > 10)
        {
            if(llGetSubString(speed,0,2) == speed)
            n1 = 0;
            n2 = llDeleteSubString(speed, 0, 0);
            display = n1+n2;
        }
        else if(speed < 10)
        {
            speed = display;
        }
        llSetText(llDetectedName(0) + " is moving at " + display + "m/s.",<1,1,1>,1);
        llSay(-99,"number "+display);
        lastSpeed = speed;
        }
    }
    no_sensor()
    {
        llSetText("",<1,1,1>,1);
    }
}

Quick Observation

else if(speed < 10)
{
speed = display;
}

Should that not read display = speed;