# Callenge: limits for price entry based on average item price

**URL:** <https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230>\
**Category:** Ask for Help\
**Created:** [September 17, 2023, 7:35am UTC](https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230 "2023-09-17T07:35:04Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Miroslav\_Madaric](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/miroslav_madaric/32/20852_2.png) [@Miroslav\_Madaric](https://community.glideapps.com/u/Miroslav_Madaric)\
**Post date:** [September 17, 2023, 7:35am UTC](https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230/1 "2023-09-17T07:35:04Z")

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I have item prices and average calculated as follows:

![image](https://us1.discourse-cdn.com/flex002/uploads/glideapps/original/3X/a/0/a08c7d0c110099b7ee1a7bdb83e252ab94f5f5a6.png)

If new item is entered using Form Screen, I want to limit price entry within -50% and +50% of average unit price. In this example, for ham would be 5-15 and Eggs for 0,20-0,60.

Calculating avrege price was easy, but I can’t find the solution for set the limits intended in real time, e.g. during the data entry for new item. It is requred that after filling of field “Item”, the limits for “Price” should be 5-15 for “Ham”!

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**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\
**Post date:** [September 17, 2023, 8:52am UTC](https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230/2 "2023-09-17T08:52:14Z")

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Will you be using a custom form?

If yes, it’s quite simple.  
If no, then I don’t believe it’s possible.

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<div class="post-metadata">

**Author:** ![Miroslav\_Madaric](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/miroslav_madaric/32/20852_2.png) [@Miroslav\_Madaric](https://community.glideapps.com/u/Miroslav_Madaric)\
**Post date:** [September 17, 2023, 9:54am UTC](https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230/3 "2023-09-17T09:54:04Z")

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I am using simple Form Screen. I am not familiar with Custom Screen, I will check it. How it helps to get information based on item during data entry?

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**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\
**Post date:** [September 17, 2023, 10:52am UTC](https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230/4 "2023-09-17T10:52:46Z")

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When you use a Custom Form, the values the user enters are written to User Specific columns, which means that you can use them to compare to pre-existing data, and control the user flow based on those comparisons. You don’t have this option with native forms, as the values are not written to the table until after the form is submitted - which is too late to take any action.

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**Author:** ![ThinhDinh](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/thinhdinh/32/49_2.png) [@ThinhDinh](https://community.glideapps.com/u/ThinhDinh)\
**Post date:** [September 18, 2023, 12:31am UTC](https://community.glideapps.com/t/callenge-limits-for-price-entry-based-on-average-item-price/66230/5 "2023-09-18T00:31:28Z")

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> [@How do I create a custom form?](https://community.glideapps.com/t/how-do-i-create-a-custom-form/25014):
>
> I’m just dropping this here so I have something to refer people to when they ask. This is a simple concept app (copyable), that demonstrates the following techniques: Building custom forms for adding and editing list items (as an alternative to the native forms provided by Glide) Preventing duplicate new entries using [User Specific Columns](https://docs.glideapps.com/all/reference/data-editor/user-specific-columns) and [Relations](https://docs.glideapps.com/all/reference/data-editor/computed-columns/relation-column) Enforcing mandatory input items The use of visibility conditions and user specific booleans to control user flow There is nothing particula…

Here’s the thread on how to create a custom form.