Can't Get Calculated Field To Display Blank When A Related Field Is Left Blank

[defaultj2i94ronq2ea]

Need to display a blank unless v1 has a number entered. Currently v1 shows -30 with nothing entered. Please help. Thanks.

var v1 = Number(this.getField("AsFoundRow1").value);
var v2 = 30;
var v3 = (v1)+.0001;
var v4 = (v1)-.0001;
if (v1 ==""){
event.value = "";
}
if (v1 =>30)
{
event.value = (v3)-(v2);
}
if (v1<30)
{
event.value = (v4)-(v2);
}

[try67 · Accepted solution]

Try this:

var s1 = this.getField("AsFoundRow1").valueAsString;
if (s1=="") event.value = "";
else {
	var v1 = Number(s1);
	// rest of code goes here
}

[defaultj2i94ronq2ea]

Wow! Fast response and works perfectly. Learned something new today. Thank you try67.