getMatrixSublistValue throwing exception

Hi,

We have a requirement where we need to get the ListPrice value from Pricing Matrix in User Event Script of Inventory Item. For this I am using the below function.

function afterSubmit(context) {

var item = context.newRecord;

var listPrice=item.getMatrixSublistValue ({

    sublistId: 'price',

    fieldId: 'price',

    column: 2,

    line: 1

});       

log.debug("ListPrice: "+listPrice);

}

But this is throwing error  as below

{"type":"error.SuiteScriptError","name":"SSS_METHOD_IS_ONLY_ALLOWED_FOR_MATRIX_FIELD","message":"Method is only allowed for matrix field.","stack":["anonymous(N/serverRecordService)","afterSubmit(/SuiteScripts/Oracle_NetSuite_Salesforce_InventoryItem_Script.js:88)"],"cause":{"type":"internal error","code":"SSS_METHOD_IS_ONLY_ALLOWED_FOR_MATRIX_FIELD","details":"Method is only allowed for matrix field.","userEvent":"aftersubmit","stackTrace":["anonymous(N/serverRecordService)","afterSubmit(/SuiteScripts/Oracle_NetSuite_Salesforce_InventoryItem_Script.js:88)"],"notifyOff":false},"id":"","notifyOff":false,"userFacing":false}